Keep up the research and make absolutely sure to take the PSATs this year, even if you also took them last year. In addition to giving you a heads up on what the actual SATs will be like, the PSATs qualify high-performing juniors for the National Merit Scholarship, which is currently worth $2,500. To boost that amount, several colleges offer additional institutional scholarships to National Merit finalists and semifinalists.
If you can, take the real SATs and/or ACTs this year, so you have plenty of time to take them multiple times before college application season rolls around, and any Advanced Placement or SAT II subject tests you may need for courses you take during your junior year. Some colleges require SAT II subject tests whereas others don't, so check with the schools you'll be applying to for info on what testing you'll need.