All PvX contributors is the freedom to vote on any build on the wiki. The vote option can be found at the top of a build page next to where it says "build", "discussion", "rate", "edit", "history", "move", and "watch/unwatch". Note that if you are not logged on, "watch/unwatch" will not appear. Note that you must have at least ten contributions before voting and have been a member of the site for a certain period of time. By pressing the "rate" button, you are taken to a page where you can vote on three main points of a build:
Effectiveness: This is about the overall usage of the build, asking two questions: "Does it get the job that it is meant to do done?" and "Does it do it well?" This accounts for 80% of the overall rating.
Universality: The Universality section is about the versatility of the build, basically asking: "Can it be changed easily to fit different scenarios while retaining its effectiveness?". This accounts for 20% of the overall rating.
Innovation: This means how original the build is. If the build or something similar has been done before then it's not original. This does not effect the overall rating, it is merely for information.
Don't feel the need to vote high or low on a build just because everyone else does. Peer pressure is no reason to change your vote. Even though your vote is different from other votes, it cannot be removed without a legitimate reason.
If you believe that another vote is factually wrong, post the reason why on the voter's talk page. Usually, this is accessible in the voter's signature. Make sure to add a link to the build. By looking on most users' talk pages, you can see examples of this. If the voter does not respond, post the problem on the Administrator's Noticeboard.
Your comment should reflect the rating you have given the build, you should not vote a build "great" and say "this build is trash". The comment you give should explain why you've given it what you have, why do you think it deservers X in effectiveness or Y in universality?. For builds you don't give a perfect score (and sometimes even those that you do), give feedback on how to improve the build "It lacks skill X, which would make it a lot better because of Y". Note that votes without sufficient reason can be removed at any time by Administrators, so ensure you have explained your reasoning thoroughly.