Circular Saw Guide
The circular saw guide is used to provide you with a perfectly straight cut while being easy to setup and use. I can't give you exact measurements for your saw guide since each one has to be built specifically for your saw.
I built mine out of scrap plywood that I had laying around the shop. I plan on building a new one eventually from 1/2" x 60" x 60" BC Plywood and will take pictures of the process then.
Basically you need some plywood with the factory edge still on it since you will base everything off that edge (Hopefully its straight). It would be best if the saw guide be over 48" long so your saw is supported before and after any cross cuts on full size plywood. Mine is about 54" long but the new one will be 60". Measure from the inside edge of your saws faceplate to the outer most edge of your saw motor housing. This will be the width of the factory edge board. Use a chalk line to mark the plywood and cut off the factory edge.
Now measure the full width of your saws faceplate. Screw the factory edge you just cut off to the the remaing plywood that distane from the edge. The factory edge must be facing the edge you just measured from. Now, run your circular saw across the plywood with the edge of your circular saw base plate against the factory edge. This will cut the remaining plywood to the exact width you will need. Now whenever you need to make a cut you simply push the saw guide up to the line you want to cut and you know that line will be cut exactly at the edge of the saw guide.
You now need to cut the remaining plywood off from the other side of the factory edge piece. You need to leave enough wood on that side so you can clamp the saw guide to your work piece. Because of the measurements we made for the width of the factory edge piece the clamps should not interfere with the saw as long as you don't clamp on that factory edge piece.