Time management is an essential skill on Wikipedia as in all aspects of life. Since your time reading and editing Wikipedia is limited, you should focus your editing toward the most enjoyable and productive goals.
Background: how much time?
According to Special:Statistics, the English Wikipedia has 2 million articles as of September 2007. There have been more than 10 million pages created, and more than 160 million edits, for an average of 16 edits per page. As new users contribute to Wikipedia, the number of edits and articles continues to expand.
It is worth taking a moment to ponder the vastness of this collaborative undertaking. Each edit to Wikipedia requires time to identify a possible improvement to an article, then time to draft the improvement, and finally a moment to add an edit summary and click "save changes."
Some tasks, such as reverting vandalism on recent changes patrol, require mere seconds to complete, but patrollers sort through several good edits before they find a bad edit. Other tasks, such as writing a featured article with references, require many hours of work.
As a thought experiment, let us assume, ad hoc, that each edit requires an average of two minutes to execute. In reality it probably takes longer, but two minutes provides a reasonable "low-end" estimate for how much time people have spent editing Wikipedia.
A user who produces one edit every two minutes will produce 30 edits per hour, 720 edits per 24 hours, and about 5,000 edits per 168 hours, i.e. one full week. Based on User:Betacommand/Edit count and similar lists, there are probably at least three thousand Wikipedians who have contributed at least 5,000 edits. Each of these Wikipedians has spent the equivalent of one full week, and probably more, logged in to his or her user account.
The collective output of 160 million edits at two minutes per edit would require 320 million minutes. Even if we account for the millions of edits by bots, it seems likely that human editors have expended 5 million man-hours or more. That's a staggering number. If the average human life expectancy is around 70 years, or 610,000 hours, it would take more than 8 full lifetimes to write the English Wikipedia as of September 2007. This reckoning does not account for deleted edits or administrative logs, or time reading Wikipedia without editing it, or edits made to Wikipedia in other languages and to other Wikimedia projects. The sheer immensity of the undertaking makes Wikipedia seem like a real-world incarnation of the infinite monkey theorem.
How not to waste time
Unless you wish to devote your entire life to Wikipedia, you need to use your limited time on Wikipedia effectively. Certain common activities on Wikipedia, though well-intentioned, may cause you or others to waste time.
- Vandalism. Vandalism wastes the time of the honest folks who have to clean up someone else's mess. It also wastes the time of the vandal because, once the article has been restored, no net change has been accomplished. For further reading, see User:Persian Poet Gal/Why Vandalism is Silly!.
- Edit warring. A revert war between two or more editors results in no net improvement to the article. You will accomplish more on Wikipedia if you improve ordinary articles instead of fighting over hotly contested articles. Formal dispute resolution, though necessary to maintain order, consumes a tremendous amount of time for everyone involved. Even if you're right, it might not be worth the time it takes to prove your case.
Good behavior, but unnecessary
- Recent Changes Patrol and New Page Patrol. Wikipedia depends on dedicated volunteers to screen suspicious edits and new pages for violations of policy. However, the question is not whether patrolling is a worthwhile activity. Rather, ask whether you should be doing it. All regular patrollers have experienced edit conflicts, finding that another editor has already reverted the vandalism or added a speedy deletion template to a new article. If you find that other patrollers are preempting your intended edits, you should quit patrolling and do something else. You may return to patrolling later, when your screening activities may fill a greater need.
- Voting on discussions when the outcome is already decided. Popular editors have received tens of gratuitous support votes at Wikipedia:Requests for adminship even after the outcome is clearly decided in their favor. An extreme example was Wikipedia:Requests for adminship/Phaedriel 2, which passed at 271/6/5 without serious opposition: the last 200 support votes were unnecessary to decide whether the candidate would become an administrator. (However, these addition comments may help build the Wikipedian community.) Similarly, at Wikipedia:Articles for deletion and other deletion debates, there is no need to write "Delete per nom; fails WP:BIO" after a consensus to delete has been established. Instead, you should look for nominations where nobody has commented yet.
- Striving beyond your user access level. If you are not an administrator, you will not help anybody by scanning the candidates for speedy deletion for the few pages that should be kept, or usernames for administrative attention to find usernames that should not be blocked. Let the admins do it. However, many inquiries at the administrators' noticeboard do not require admin access to address them, and can be investigated and resolved by any user. If you wish to help the admins, bureaucrats, checkusers or arbitrators to do their jobs, make sure you are saving them time instead of just following steps they will need to take for themselves.
How to use your time effectively
There are many ways you can improve Wikipedia. The Community Portal lists some collaborative projects and maintenance backlogs where you can contribute. You should focus on doing work that nobody else is doing. Taking leadership of deficient articles, projects and portals is probably the most efficient way to spend your time editing Wikipedia.