I began thinking about the SAT in the fall of my sophomore year. My school allowed sophomores to take the PSAT, which is the National Merit Scholarship Qualifying Test and a shortened practice version of the real SAT. This test takes place in November; make sure to ask your school counselor if you can take it. I bought the two books in my SAT Library (actually older versions of them) and read the Princeton Review book before the test. It gave me a good overview of the test and made me much more comfortable with taking it.
In the fall of junior year, I took the PSAT again (this is the normal time; if at all possible take it then at % ). I took the SAT for the first time the following month. I felt I could do better than the score I recieved that December, so I signed up to take the January test, the one I aced. Needless to say, I didn't sign up for any more SAT I tests.
I would recommend not starting too early (9th grade or earlier) or too late (senior year) for testing. Of course it is still fine and even recommended to do things like the TIP program, if that is available. Junior year seems to be the perfect time to begin because you have those years of high school education and maturity behind you while you still have plenty of opportunities to take the test. And you must take the SAT more than once, since almost everyone substantially raises their score that second time. But I've also seen students take the SAT too often and get burned out as their scores stay near the same test after test.
So if possible, take the PSAT in November of your sophomore and junior years. Then start taking the SAT in the winter of your junior year, taking it several times until you feel you've done as well as you expect you will without obsessing. I can tell you from the experience of several of my friends that colleges will look beyond your test scores and truly care more about your extracurriculars, community service, and grades. But the SAT still is important, so try to do your best.
As for specific advice for either the math or the verbal section, my best advice is practice. That's actually why I made this page in the first place! And it's best if you can make your practice as much like the real test as possible. So time yourself and don't have any distractions (go to the library, close the door to your room, etc.).
If you take a verbal practice test and don't see a word you don't know - look it up when you are done. When you take math practice test, figure out what you missed: try it again, ask someone, look it up in a book. Then next time it will be easier!
Most all, don't worry too much, especially on the test day. Remember that there are more important things!
E-mail me at jasondonald @ hotmail . com