Only one GFI is needed to protect all the outlets on the circut. Once one GFI's been installed any other outlets down stream for that one will be protected.
If it was mine I would be running 12-2 with ground, use a 20 Amp. breaker.
When you open up the GFI there will be a piece of yellow tape over two of the terminals. That side will be marked load. You connect the incoming power to the line side and use the load side for anything that get protected down stream from there.
Reguler outlets are fine.
There is no limit to the number of outlets you can have on one circut, but it's common to see two differant circuts run, one for each side of the building.
If your going to have an outside outlet I like to have the line run from the breaker box to a GFI that's inside the building then run a line to the outside outlet. Reason being there's a lot less chance of faulse trips from moisture getting in the GFI.