Khan Academy has tutorials, lessons, videos, and practice problems for a lot math stuff.  I think I explain things a little easier, but they can help too.  Here is their link:

The ACT is another common test for getting into college.  It covers the same math as the SAT and TSI.  They have five practice tests.  Here is their link:

The SAT Test is written by The College Board.  They are a big company and have 8 practice tests online, they have the answers and explanations, and they will tell you how to calculate your score based on well you do on the practice tests.  Here is their link:

Mr. Lake's Math Site