A.C.T!

First, take a pre-test. You can buy books at the bookstore or likely find one on-line. Just knowing what the format looks like is valuable. Next, practice going at a decent pace. This is a timed test. It's not very aggressive timing, but if you try to be extra, extra careful and triple check every answer, you will run out of time. Third, don't be afraid to guess. If you can narrow a problem down to two or three possible answers, pick one.

Great! Thanks very muchhh (:

Classes can be expensive, but if you can afford they can help. Sometimes just knowing what to expect can ease the nerves so if you cannot afford a class then try getting a book like suggested so you can prep.

My daughter is taking an online class for SATs which tends to be a little less than in a classroom setting - also allows you to go back and view the video of the class later on.

Do several practice tests. Set yourself up the way you will when you write the test i.e. if they don't allow drinks, don't have a drink with you; if it is a quiet setting, practice without music. Replicating the physical test setting as best you can seems to really help (lots of studies on this).

When I prepare for similar types of tests, I do one practice one each weekend for a couple of months. I make the rules for myself tougher as I go along.