To the OP:
As mentioned, load up on Math and Physics. The more you get done now, and keep with it, the better off you'll be. Also, if you want to see a glimpse of the stuff you'll be getting into, do a google search for the NEETS Modules and download them; they're in PDF format, and there are 23 (I think) of them. Read through them, study them, etc. This will give you a head-start on the stuff you'll learn in college when you start the degree program. Plus, if you knock out the AP Calculus and Physics classes, those are a few less classes you'll have to take in college.
You'll also want to start tinkering a little with computer programming; C, C++, Java, etc. Even if your degree is strictly Electrical Engineering (or electronics), you'll be required to take some computer programming classes.
I'm in the process of getting my Electronics Engineering degree now, plus I spent 10 years in the Navy as an Aviation Electronics Technician. I didn't figure out that I wanted to do the engineering thing until a year before I got out, but once I did...the one thing I did regret was stopping at Algebra 2 in High School....lol. Going through Algebra again was a royal pain, but once I got to calculus, it got easier -- if you already have that knowledge when you hit college, you'll be SO MUCH better off.