As a senior in high school, I have a valuable bit of advise to offer you all:
Try to get your college admissions tests out of the way toward the end of your Junior year/during the summer between Junior and Senior year. Why, you ask aloud? It makes Senior year somewhat less hectic, what with all the research/visiting/applying to colleges, not to mention the grueling demands of 12th grade/college level (AP/IB) coursework!
Also, many colleges have their most prestigious scholarship deadlines within the first few months of your senior year, and these said scholarships often depend largely on SAT scores (as well as academic achievement and extracurricular involvement!). So if you've taken SAT once in June and received an okay score--one you know you could add 100-300 points to--take it again and as soon as possible so that you can apply and have better chances with Early Decision/awesome scholarships with early deadlines.