Skill areas that are covered by the test are:

Elementary operations with numerical and algebraic functions
Operations with exponents and radicals
Linear equations and inequalities
Polynomials and polynomial equations
Functions
Trigonometry
Logarithmic and exponential functions
Mathematical modeling -- word problems.

On-line Practice Test: http://mdtp.ucsd.edu/crtest/

Recommended algebra/trigonometry refresher books:

Just-In-Time Algebra and Trigonometry for Students of Calculus, 2nd Edition by Mueller & Brent. Addison-Wesley ISBN: 0-321-26943-8