How to complement a dish? I really love cooking the "main feature" of a meal...  I love doing the meat - steak, chicken breasts, you name it, I love it.

But when it comes to making the rest of the meal, I always draw a blank. I end up resorting to the same old thing that I know everyone loves (steamed asparagus, seasoned potatoes).

I'm trying to figure out how to be more creative with the complementary pieces of the meal.  

What are some good things to keep in mind when preparing a side dish, and what are some good resources that will help me in my creativity?
You could certainly get a cookbook of side dishes and learn some new favourites, but what might be more useful is a book that teaches you about flavour combinations and menu planning.  I would suggest Culinary Artistry as one such book.  It's not about specific recipes (you can find those elsewhere or make them up), but rather it addresses the kind of skill you're looking to learn.

One technique is to consider the origin of the main dish and choose side dishes from the same region.  Seasonality or market-based shopping is another approach to expanding your repertoire.