I'm working my way through Andrew Loomis's "Figure Drawing For All It's Worth" and found myself stuck on page 30. There he shows how to draw a figure in perspective using a divided box for guidance. It seems that the online community was as confused as me so I broke the methods down into step-by-step instructions in two parts. See my blog posts if you're interested!
Tell me if these help you or if they can be improved in any way. Thanks!