I left my camera cable at school so I'll have to get pics some other time, but the basic idea is you lay out your angle on the workpiece (what you want to cut). Find a scrap panel that has a straight edge on it, lay it out parallel to the line you want to cut, but have the scrap board wide enough that way you can run it along the fence as your straight edge. Voila you have your workpiece cut at whatever angle you ran your top board at.
There are different ways of attaching your two pieces together. I've always just nailed it (leave it long so there is a place to nail it to without leaving a hole), but I think that the 3M adhesive strips that are made to hang posters and not leave a mark would work excellent if you don't want to nail it.
That should be a good enough explanation for a competent wood butcher to follow. *If not, tell me what your confused on*