SAT: collegeboard.com
ACT: actstudent.org
ISEE: erbtest.org
SSAT: ssat.org
HSPT: ststesting.com

Upcoming dates for ACT and SAT:
SAT 01/24/09
ACT 02/07/09
SAT 03/14/09
ACT 04/04/09
SAT 05/02/09