I can only speak for myself, but there is a guy called Taugrimm(http://taugrim.com/2011/04/07/guide-to-strafing-movement-and-keybindings/) that explained it well, he also gave examples and explanations, what I used as a template. There is also a video from a guy called swifty(
) that actually showed him using the mouse and W,A,S,D together. That worked for me. Don't worry about the hardware, I have none of those things and the mechanics still work. I hope that helps.
I also unbound S, Q, E, C,X,Y and Z and placed skill-functions on them. That way I have all needed skills for combat reachable. Here is an example of a setup I tested: http://i44.tinypic.com/15n3hty.png A and D are used now for strafing(I changed a few things at present), but that was some of the testing I did. You can bind strafing to anything as long as you are not confusing yourself. Set up the keys to what works for you(reaction, flexibility and reflexes mental and physical). You know yourself and abilities better than anyone on this forum.