If you are trying to learn how to make a natural looking walk cycle, Joeri points us to this site, Biomotion Lab. Biomotion Lab has created a real time walk cycle model where you can adjust the various parameters such as male / female; heavy/light; nervous/relaxed, happy/sad.
In addition, you can rotate the model on the Z axis as well as add lines between the marker points. I also like to make copies of the walk cycle creations for future reference using Cam Studio
Other sites to consult on walk cycles: