Check out Domarius' animation reference footage
idleworm tutorial 2D walk cycle, contains useful info about focusing on contact points and recoil.
centre for animation & interactive media tutorial A variety of very different walk cycles, which can be viewed by rolling over with the mouse.
anticz tutorial Nice simple breakdown, re-affirming what's learnt in the previous links.
Preston Blair Walk Cycles "these animation cycles are almost canon in the industry, and can be found in a large percentage of any animation book that you might pick up." I noticed they're very cartoony and exaggerated, but this is good to see the kinds of movements that can go on.
Curved paths in Motion Builder for smooth movement - Plot paths manually or with keyframes, and have objects follow the path. Not that useful because it doesn't work with limbs, but could be useful for prescripted anims.