What’s the best study guide for the GRE psych subtest?

Have you taken the psychology subtest of the GRE? Can you reccomend a good study guide?

When can i register for the GRE subject test?

I need to take a GRE subject test in psychology. On the website, it says registration is closed. How and when can I register for this test?

Thank you.

What is the best book to use to prepare for the GRE? Princeton, Barron’s, Kaplan, or other books?

This will be my first time taking the GRE and I am wondering which book is better in preparing you for the exam. I’ve already bought a Princeton 2010 GRE book but was wondering whether I should purchase another book (such as Kaplan, Barron’s, or some other book). Which books, study habits, and test techniques helped you? I am wanting to get an M.A./Ph.D in Psychology as I am a double major in Psychology and Human Development with a Minor in English. Thanks!