The locations have all been covered, so on to the other stuff...
First, if you are a competitive type and want to set yourself up for success, equipment counts. You don't have to spend an arm and a leg to go fast, but you do need to have proper fitting boots and skis that will carve and reward while not being too far outside your skill level. Boots that are too loose and skis that aren't designed to carve will have you pretty frustrated. Start with your boot fit, it's the most important part of your equipment to nail down for racing and skiing in general. If your boots are toasty warm, comfy and easy to get on and off, chances are they are too loose. If you have the means of buying boots, consider doing it or at least take your existing boots to a good shop and have them evaluate your current fit given your intentions of starting to race. A good boot fitter will let you know where you are at and what your options are.
Second, race more NASTAR, clinics, etc. The guys and gals you see lined up at the shack on weekends are there because they love it and most are happy to give pointers and advice if you ask for it. Some places also offer drop in race clinics that will get you up to speed even quicker by giving immediate feedback at the bottom of the hill and some even review video so you can see what you are doing.
Third, have fun, stay humble and realize that improvement is inconsistent. You'll have days where everything clicks and ones that feel like you have two left feet. It's called ski racing, not ski winning, nothing comes for free and without frustration. No matter what, it's a lot of fun.
So what is your skiing ability and your athletic background?
And of course, welcome!