Take a side walking tutorial, then rotate it 90 degrees towards you
Sorry, that isn't very helpful. If you do a google for Muybridge you'll find a ton of animations of [naked] people walking and doing all kinds of stuff from front, side and back angles. Find a person walking forward, copy their walk then add some push, pop or whatever else you think necessary to make it interesting.
And I didn't realise it until now, but there' a link to an animation book by Preston Blair in the Tool& tutorials/Resources thread. A google for animation principles will also bring up a lot of useful information.
Sorry that I don't have any tutorials, but I'm sure you'll find the above interesting and more helpful when you need to do a walk cycle from the back or any other kinds of animations.
