General Requirements
The algebra book must be no more than 400-500 pages in length and should contain end-of-lesson/chapter exercises.
Required Topics
- linear equations
- linear inequalities
- graphing and analyzing linear functions
- systems of equations and inequalities
- multiplying and factoring expressions
- quadratics(everything about polynomials)
- functions
- ratios and proportions
(and even more if the book has it...)
Gelfand's Algebra book is fantastic. It is written for the student to enjoy.
Lang's Basic Mathematics also sounds like a good choice. It's between 400 and 500 pages, but contains more than you asked for.
The Art of Problem Solving algebra and precalculus books are very good, if you're looking for books with a contest prep focus (they're still great, if not).
Alternatively, you could work through Khan Academy's knowledge map.