KSH, like you, my legs definitely look better from cycling so I don't disagaree with you. I have to wonder, though, if some of the increased definition is from weight/fat loss rather than muscle growth. Either way, I'll take it. Thanks to cycling, I've lost and kept off about 7 pounds, and my thighs and hips are noticeably thinner. I doubt that they'll ever look really "cut" though; that's just the way I'm built. However, if I just look at people doing sit ups, my abs get toned. There's no accounting for genetics.

One book that I like as an intro to both indoor and outdoor cycling is Bike for Life by Roy M. Wallack and Bill Katovsky. It has a lot of useful information about training for fitness (rather than for competition), suggestions for specific exercises to supplement cycling like resistance training and yoga, nutrition, indoor cycling, cycling skills and the like. It's a good all-around, introductory book.