I just noticed that I now have a review option in my menu bar on SE. How did I get that? Also please can someone point me to where the guidelines are for reviewing posts?
You got the review queues because of your reputation level. The guidelines are the same as they were before when using the site. The queues just bring the attention of experienced eyes to posts that frequently have problems.
Depending on your reputation, you will see suggested edits, questions with close votes or off topic flags, first posts, late posts (answers on old questions), posts flagged as low quality and questions that are up for consideration to reopen (have either been edited of had someone click reopen).
You can do all the same stuff you'd normally be able to do on them, the queue is just a way to make sure they get looked at. If you don't know if it needs action, you can always just hit skip and it will leave it in the queue for someone else to look at.