Get a couple of REALLY good cookbooks. I have listed these before, so sorry if you've seen this before, but I really love, "The New Best REcipes" by the Editors of Cooks Illustrated. I like it because it doesn't only give you a recipe, but also tells you how they GOT to that recipe, and why they use certain techniques in certain recipes. Soooo, I've learned a lot from using the book. Even if you're a good cook (and I think I was) I challenge you to use this book and not learn something you can take with you at least now and then. So, also, "How to Cook Everything" by Mark Bitman is good. He has great recipes, too, although maybe not quite as educational as the Cooks Illustrated one. One of my favorite vegetarian cookbooks it "The Modern Vegetarian Kitchen" By Peter Berley. I have two slow cooker books I like...can't remember the one I like second best, but my favorite is "Not your Mother's Slow Cooker Cookbook."
Getting good books will help you to get the basics down. They have things in them like how to make broth. Broth is a great thing to have around the kitchen, and knowing how to make your own is a great tool. And it works up from there...
Meal planning helps, as does organization in the kitchen, and having really good spices and herbs and basic pantry stuffs to work with...it can make the final product significantly better. This doesn't mean to buy the most expensive brown rice, or whatever (I buy in bulk), just that the small stuff is sometimes worth it and can go a long way. Actually, I buy many of my spices from Penzy's, which is usually much less expensive and much fresher than grocery store's.
Shopping for fresh things once or twice a week is good, as is leaving the rest to large shopping trips and planned sales trips.