I recommend the America's Test Kitchen/Cook's Illustrated series of cookbooks. They aren't really beginner level, but they're not super hard. And every book in the series has an article before each recipe that explains WHY each recipe has the ingredients and techniques used. They're great for learning how recipes work instead of just mindlessly following directions. Make a few of the easiest recipes and you'll soon learn to understand cooking in a fundamental way. I strongly recommend "The America's Test Kitchen Family Cookbook" as a first step, and also "The New Best Recipe", which is my favorite general interest cookbook.
Everybody have fun tonight. Everybody Wang Chung tonight.
I started learning thanks to my habit of trying everything in the kitchen out of curiosity as to what it tasted with- including getting yelled at by my mom for eating the spices out of her spice cabinet when I was younger
After that it was trial and error with various recipes found in my mom's recipe box, different cook books and random combinations of things that seemed like they would be good together- when the dish was good I remembered it, when it was bad, my mom tended to tell me what I did wrong
after you get the basics down, cooking is pretty much just theme and variation on certain processes and ingredients
I'd also suggest Good Eats to learn more about the ingredients... Alton Brown is AWESOME!
Human beings make life so interesting. Do you know that in a universe so full of wonders, they have managed to invent boredom? -Terry Pratchett