How I edit
This is a guide to how I edit, as a courtesy to other Wikipedians. After being employed as an editor for a government-affiliated bilingual periodical overseas, and then for a group of trade magazines about various manufacturing industries, I returned to the United States and edited an academic journal while pursuing my postgraduate degree. Thus I approach Wikipedia editing as a professional or scholarly task, even though it is fun recreational volunteer work for you (I hope) and for me.
We are here to build an encyclopedia, so let's discuss how to improve as many of the 5,073,561 articles on Wikipedia as we can. One thing I have learned from working in editorial offices is that every writer needs an editor—including a writer who is also an editor. A writer writes, with the writer's intention, and then a reader reads, perhaps inferring a different meaning from what the writer intended. A writer can learn from an editor how another reader interprets what the writer wrote. That's why I'm glad to discuss with other Wikipedians what I write on wiki. Your comments are welcome on my user talk page.
Seeking and verifying sources
I like to edit according to reliable sources. For article text on topics that relate to human intelligence or health or genetics, I edit that text according to Wikipedia source guidelines on medicine. I collect source lists to share with you and other Wikipedians so that we can discuss what the sources say and what implications the sources have for improvements in article text. You are welcome to suggest additional sources on the suggestions page for each source list. You are also very welcome to post on my user talk page your comments about my edits. It is possible for reasonable minds to differ about what is an appropriate edit, and I welcome your comments so that I can learn from you.
Please remember that by Wikipedia core policy, extraordinary claims require extraordinary evidence. Your favorite political blog or fringe theory website is not a reliable source on any subject, and especially not a reliable source on issues related to the point of view it pushes. Part of editing an encyclopedia is learning how to use the fact-checking sources that grown-up encyclopedia editors usually use—professional reference books of the kind that are usually found in university libraries. The World Wide Web still doesn't post full text of many of the best products of human research, and plenty of accurate information about the world is completely unknown to people who haven't gone looking for it. So let's discuss collaboratively what the indisputably best sources say about issues that are often harshly disputed.
Promotion and conflicts of interest
A problem that has beset Wikipedia since Wikipedia gained in popularity as an online reference tool is articles that are thinly disguised advertisements. The Wikimedia Foundation had to fire a staff member after the foundation staff member accepted paid Wikipedia editing jobs on the side, and there are doubtless still thousands of articles on Wikipedia that are little better than poorly disguised advertisements, whether written by a paid editor or written by a "volunteer". You can use the advertising template and apply it directly to the top of any article page that looks and smells like an advertisement. There are plenty of articles that need this tagging for Wikipedia to maintain its own reputation.
Related to the concern about misusing Wikipedia as an advertising or publicity channel is Wikipedia's behavioral guideline about editing with a conflict of interest. I have friends, relatives, and business clients, and I suppose you do too. It's natural for anyone to want to look out for the interests of friends, relatives, and business clients and colleagues. But the Wikipedia behavioral guideline on conflict of interest says, "Do not edit Wikipedia in your own interests or in the interests of your external relationships." I watchlist some pages on Wikipedia that are about organizations I have joined or people that I know in person. I watchlist those articles strictly to revert unambiguous vandalism, and to keep up with the news (as it appears on Wikipedia) about those organizations and persons. I do not edit article text in articles about those organizations or persons, but leave that task for other Wikipedians. There are plenty of Wikipedians (well, we could always use more) without personal conflicts of interest to edit the subset of the 5,073,561 articles on Wikipedia that they have no strong personal ties to. I keep my friendships, employment and contracting relationships, teacher-student relationships, and relationships with close relatives from influencing my editing on Wikipedia by not editing any article text that impinges on those relationships.
Basic editorial competence
Here on Wikipedia, every editor begins with a first edit, and aside from some spectacular examples, most editors have some idea of what they mean to do to improve the encyclopedia. The way to gain competence is to read the documentation, especially the information page on Wikipedia editing norms and the policy about what Wikipedia is not. The Manual of style is a crucial document to revisit frequently, as many Wikipedians have habits from school or from jobs that are not standard editorial preferences here on Wikipedia, and some editors waste a lot of time changing correctly styled text into forms not required or not even approved by the manual of style. Basic editorial competence counts for a lot here.
I try to minimize errors (but I'm sure I still make a few, so feel free to point out my errors) by doing most of my editing in off-wiki drafts that I keep on my personal computer. I preview those and tweak them, almost always, before submitting them to Wikipedia. That makes my edit count look misleadingly low, but that's okay, because I don't judge editors by their edit counts. "Quality, not quantity" is the correct rule for evaluating edits to Wikipedia.
Communicating with other editors
Some of the topics I try to edit have been plagued by edit wars since long before I became a Wikipedian in April 2010. At least a few of the most viewed articles on my watchlist have actually declined in quality for long periods from 2009 to 2013, as the result of deletion of content from reliable sources, although some have improved a little since the year before I began editing Wikipedia. To give editors a chance to check sources in advance, to avoid article content being cited to sources that don't actually support article text, I generally first list sources on the source lists for sharing with everyone here. If you have access to a decent library (especially a library with interlibrary loan service), you can obtain a copy of a source yourself to verify it. As I continually read and digest sources, in an order of reading sometimes constrained by library due dates, I often first add sources to articles in the articles' Further reading sections, which I sometimes create for that purpose. This, again, allows other editors time to gather the sources themselves and verify that the sources have information that adds to what is posted in article text (as will always be the case if I add a source to a further reading section). Many of my friends have reminded me that good print encyclopedias often have further reading sections at the end of an article, and I have seen hundreds of examples of those. One of the best ways we can improve Wikipedia for all of Wikipedia's readers is by looking for good sources, and using those to update articles, mentioning the best sources along the way in the further reading sections of articles.
As time goes on, I gradually make direct edits to article text, whether WikiGnome edits or bold edits, based on the sources I have at hand. I also make extensive use of source verification templates, especially the template for tagging primary sources that aren't backed up by a reliable secondary source, to alert other editors to article content issues that need additional verification. There have been some notorious instances on Wikipedia of editors inserting hundreds or even thousands of fudged sources into articles on a variety of topics, so I think all of us editors have to be aware of how to check sources. The Wikipedia Library is a very helpful resource for editors who care about checking sources and verifying that Wikipedia article text is supported by reliable sources. We all need to be alert to verify that the sources are being used in accord with what the sources actually say. In all cases, you can reach me by a new message to my user talk page if you'd like to discuss sources for specific articles or article text edits further. Comments on the article talk page of each article are also fine, and may be better for including other editors in the discussion, as I am happy to do.
Hope for the future of Wikipedia
I want to thank experienced Wikipedian and administrator rʨanaɢ for pointing out the quotation below (from Wikimedia Foundation's Public Outreach Officer and Wikipedia administrator Peteforsyth) on his user page:
I think this is a very hopeful statement. We can learn together as Wikipedians how to reach a higher standard of online behavior. We can verify information better than is done in blog comments (or even blog articles by the rare experts who maintain blogs), treat one another more civilly than is done on most online discussion forums, stay more serious (while still enjoying ourselves) than is usually done on social networking sites, and generally contribute better to the broader world on Wikipedia than we can on most other online sites. The community helps Wikipedians become better editors. Wikipedians who become better editors, in turn, build up the content quality and participation on Wikipedia, which are explicit goals of the Wikimedia Foundation. It's delightful to be part of a project in which conscientious volunteer work by thousands of editors can help readers around the world by the tens of millions.