Dan, I like to use a #5R, which is a reverse tooth. It will cut fairly fast in 3/4" pine and should leave a fairly smooth edge and no tear out on the bottom. Crosscut will be faster than going with the grain. Speed from 1000 - 1800. You'll have to experiment as every saw (and owner) is different. Keep the blade tension in check. Tight enough to keep the blade from wandering and not too tight so it SNAPS during a cut. That'll get your attention!
The smaller blades will require less tension than the larger ones. I have a Dewalt Saw and usually ~twang~ the blade...usually to a C Sharp. LOL!
I'll second Flying Dutchman Blades from Mike's Workshop. That's all I use.
It will take a little trial and error, but looking at your sign work you won't have a problem.
Enjoy the saw other than cut-outs for your signs. Lot's of fun.
The trouble with quotes on the internet is that you never know if they are genuine. - Abraham Lincoln