The other things that bother me about a PDF layout guide is that it is going to be tied to a piece of software if it is going to be useful and that it might lead to lots of identical looking games. Still contemplating this.
Still pondering. I think the difficulty is making it into a how-to guide for the free RPG enthusiast. How do you make it useful for someone who wants to know just enough to make their game look nice without having to spend evening upon evening fiddling with layout. Some authors love that side (I do) but for those who don't, the guide should make it easy. If you have a passion for layout then you'd probably take keen interest in learning up without a for-novices guide.
I'm still not sure if I agree with myself about this. Looking back through the many RPG-tagged emails in my gmail account, I do give hints and tips about layout that often go far and beyond what my guide suggests.