Should I Start Preparing for the SAT before Freshman Year?

The only reasons to start prepping for the SAT before freshman year would be:

1. you were targeting one of the talent-search programs for 8th-graders, which use the SAT as a qualifier.
2. you were dead set on achieving National Merit recognition

In which case additional prep might be warranted.

When To Start Test Prep

For high school students looking to use the SAT as an admissions test (as most do) Sophomore year makes sense to start prep because:

1. Most sophomores will be learning the math needed for the SAT/ACT (Algebra II and Geometry)
2. It allows you to start prepping before the intensity of Junior year sets in

If you will not be taking the math you need for the test during sophomore year, then you might want to wait, or budget some additional prep time to learn that math.