I am putting together a corner shelf unit, and am curious the best way to attache the face frame; normally I use pocket holes for this - can I still do that even though the 2 pieces will be meeting at 45 degrees instead of 90? Would I just use a shorter screw? I do not have a biscut joiner, so that is out. I do have a brad nalier, but the sides will be plywood, and I am wary of nailing into the edcge of plywood... should I be?
Biscuits would be my first choice but w/o a biscuit joiner that is out. Nails shouldn't damage anything but pocket screws will give a much stronger joint and will not leave any holes that need to be filled. It's just a matter of starting the hole at the right location -- you'll probably need to set the jig back from the 'outer' edge of the miter to get the screw to come out near the middle of the plywood -- and using the right length screw. I'd try the first one in some scrap then once you've got it the way you want, it should go quick.
Edit - I agree with Red, I'd put a bead of glue all the way around the face frame. Even though gluing to a plywood edge won't add much strength, it doesn't hurt.