I’ll second the advice to get a glass carboy. Plastic can be used (make sure it says “Food Grade” on it; do not use the hardware store paint buckets—alcohol, being a solvent, will eat them) but glass is better. And once the plastic gets scratched inside, even a little bit (and it will), it will be impossible to properly sterilize them.
And get Charlie Papazian’s excellent guide, The New Complete Joy of Homebrewing. It’s the best, and most entertaining book on the subject I’ve seen.
His mantra is “Relax. Don’t worry. Have a homebrew.” Great advice. Remember that it should be fun, not stressful. And it ain’t rocket science. It’s a lot easier to brew great tasting beer than most people imagine.
Oh, and a final note about those starter kits: nothng wrong with them, for your first couple of batches anyway, but don’t be afraid to add stuff—more hops, flavoring, specialty malts, whatever—if you feel like it. Experimenting is fun.