Watch the Eric Clapton online guitar lesson by Jeff McErlain from Kings of Tone
You can experiment as to where you want to put your wah in the signal chain. I usually place it first unless I am using a germanium fuzz, then I would place the fuzz first. That particular fuzz circuit does not react well to pedals coming before it. Some people prefer the wah after distortion, I don't mainly because the classic wah users would usually be getting the OD from the amp so the wah would have to come first.