For Sale:
Pre Calculus - Larson ( if you never seen calc. before)
Calculus 8/9 e - Larson
Intro to differential equations -
For Free:
Google "Paul Dawkins notes"
His notes, follow the outline of the books i mentioned above.
Seriously. Took me from dev. math to enrolled in a Masters degree in EE
mathcentre.ac.uk is a decent site covering up to high school
here is my current year 1 Elec Eng Maths lecturers webpage, has some brilliant notes on: Series (Binomial, Taylor, Fourier), Hyperbolic Functions (diff and integration of them too), Newton-Rhapsom, 1st and 2nd Order Differential Equations, Double Integrals.
As Bill said, the CRC books are somewhat of a standard -- but I've had a few fall apart with heavy use -- they only last about a decade or so. And after reading about how CRC Press treated Weisstein, I've decided I'm not buying any more CRC products.
Two other books peek out on my bookshelf that I'd recommend. One is Bartsch, "Handbook of Mathematical Formulas" (Academic Press). I got it for $14 in 1979 and it has paid for itself many times over.
The other is Gradshteyn and Ryzhik, "Table of Integrals, Series, and Products". Mine is the 4th edition, 1965.