If it comes down to calculator needs or how-to support for particular problems, this page should be a great resource for your Math courses. You may not need to look at them all, but perhaps one style suits your needs and tastes better than another.
ARC- Aspect Ratio Calculator
Tutorials & Practice
Khan Academy - There are quite a few to choose from as well as opportunities for practice.
That Quiz - Quiz topics for practice
Purple Math - This is a Math Forum where you can start an account and ask questions, or look to see if your question has already been asked and answered. Getting help from the online community is a great way to find answers when you are stuck. There are forums here for all levels/subjects of Math.
Math.com - A thorough selection of online help for various Math subjects. Choose what you'd like to see on the left under Select Subject.
S.O.S. Mathematics - Another resource for all Math subjects that provides tutorials and explanations.
Algebra Help - Use the Lessons section for help.
GeometryThink Quest- Explanations & Examples for all things Geometry. You can see the Introduction to Geometry here, but the background may make the text difficult to read.
For Math resources, there may not be a more powerful tool than Wolfram Alpha. Check out the Math examples. For many problems, Wolfram Alpha will show you the answer, the steps it took to get that answer as well as graph the answer for you and show you all kinds of other relevant data.
Wolfram Alpha requires that equations are entered in a particular way. For example, the polynomial: x3+x2y+xy2+y3 must be entered as x^3 + x^2 y + x y^2 + y^3. It takes a little practice to learn how to use, but once you do it can be better than a calculator in many ways.