You need at least 500 reputation to review Suggested Edits.
Once you hit 500 reputation in the private beta, or 1000 reputation in the public beta, you'll be able to approve suggested edits in the review queue, or by clicking the edit link on the post.
In other words, you can vote to approve any suggested edit on questions and answers, even on posts that aren't your own. Editing is a big part of making Stack Exchange Q&A great, and it's been known to get 0 voted questions and answers many more upvotes than they would otherwise and help waay more people find answers to their questions.
If a suggested edit is pending on a post, the edit link will appear like this if no one has yet voted:
edit(0)
Click the link to view the suggested edit.