If you go back and learn Algebra, Trig, Geometry, then I fully recommend the Cliffs Study Solver series of textbooks because they are very cheap and very thorough plus each day you do a chapter, you'll make cumulative progress.
You are introduced to a concept, given a set of practice problems to see the concept in action, then given a problem set to solve on your own.
You are introduced to a concept, given a set of practice problems to see the concept in action, then given a problem set to solve on your own.
http://www.amazon.com/Algebra-I-Cliffs-Study-Solver/dp/07645...
Each book is about 350 pages and you'll be up to speed in no time.