Entire books are written on the subject. There is plenty to talk about, such as muscle types (skeletal, cardiac, smooth), muscle fiber (fast twitch, slow twitch...type I, type II...Type IIa or IIb)... yeah, we can't discuss all that in one brief article! So, let me just make a simple suggestion: Try to increase strength in ALL the muscles you can!
In weight lifting, there are basically two types of workouts; heavy weights with fewer repetitions, and lighter weights with more repetitions. However, either type of workout is insufficient (even harmful) unless the whole body receives equal attention (to some degree). For example, if you only do push-ups and bench presses and neglect working out your back, you will start to hunch over and be subject to back problems. If you work your biceps and neglect your triceps and shoulders, you'll soon put your shoulders out because they can't handle the weight that other muscles are trying to work. They all work together.
For gaining overall strength, good posture, and even an added cardiovascular workout, go to "workout routines" and try the whole body, cycle work out. (I will try to add some pictures or demonstrations later):