Since your origional post seems to be about developing your skills for the good of your "racing future" I thought I would bring up something I find very important to becoming a well rounded driver.
Get to as many tracks as you can. Run carpet, new and old. Run asphalt, new and old, hot and cold. Run indoor and outdoor. And yes practice is good.
The differences from track to track can be huge causing you to have to realy work on set-ups. This is a much needed skill.
Until this winter I had only ran asphalt. I was quite comfortable running on asphalt no matter where I was. But then on my first day of runnin rug, wow, what a slap in the junk! I basicly tested and tunned on the car for like 6 hours before I had it to a point where I felt comfortable with it. So, I went back to that track every chance I had to learn more and more.
Now, with the asphalt (outdoor) season just around the corner I feel even more confident than ever as I have learned so much about my car and set-ups in general. Sure, Im no Massami or whatever, but Im certanly not afraid to try something new on a car as I have a good idea what the results may be.