SAT/ACT Preparation

Register for the SAT here.
 
Register for the ACT here.

There are also a few free practice websites and many websites that charge various fees for practice tests, flashcards, and other study tools.  Here are a few free practice websites:

www.4tests.com/exams

www.testpreview.com/act_practice.htm

www.testpreview.com/sat_practice.htm

actexampracticetests.com

freetestprep.com