It seems the most common problem people have with math is a mental block.
You have to keep a positive attitude and an open mind with math. Don't let people scare you with stories of "how horrible Algebra is" or that "geometric proofs are a waste of time" or that "word problems are stupid" and "fractions are pointless". Most every application in math has a purpose (although you really aren't likely to use calculus at all in the real world unless you are a certain kind of engineer or a math teacher--if you have the option in high school, take stats instead of calculus, especially if it counts for college credit).
I've got a friend who says he is no good at math. However, he can do pretty well if he actually tells himself that he's good and gets some help when he needs it. For as bad as he thinks he is, he usually got a B in his high school math courses and aced tests he got help for (and by help, I mean from someone other than the teacher--I used to work on assignments with him at lunch).
Now if you really aren't good at just mathematical thinking, what you need is practice. Another buddy of mine had that problem (in every one of his classes, actually). However, he got instructions to do extra work for a semester. He wound up getting A's and B's in math (and science, with the exception of physics) all throughout high school.
And if you don't do any work in math it shows. A friend who had an A average in Algebra decided to take Algebra II and geometry at the same time. He worked hard in Algebra II and got an A. He slacked off in geometry and barely made a B. (He also had a 0% in economics for a short time since he didn't hand in his first three assignments).
I used to use computer programs to get ahead in math. There was a big set of CDs called Mind Power Math, not sure if they still make them, they had a course in every area of high school math plus Calc I (which you can use in college). No stats CD, but lots of good examples and practice problems. There was also an old Math Blaster spinoff called Geometry Blaster, which has to be the best program for proofs. And if you find you can't do your arithmetic without a calculator, better dust off that old copy of Math Blaster (I actually still have mine--as well as my copies of Carmen Sandiego, Oregon Trail, and Number Munchers).
