[villagetinker]

OP,
There can be multiple GFCI's in the garage, we have 3, check all of them, press the RESET button, if you hear a click, that is the one that was tripped.
There was a report about a house that had a GFCI by the A/C unit, and THAT one was also used for another outside receptacle.
There are some houses with GFCI circuit breakers, check these, turn fully off, then back to the on position.
As for the electrical wiring diagram, if your house is in Sumter County, you can go to the Goverment office (copper topped building) in Pinellas Plaza, and go to the building department, it should be on file.
As noted above, also check the bathroom and kitchen GFCIs, just in case the problem receptacle was tapped off one of these.
Also, you can go around the house with a lamp or circuit tester, and see if other receptacles are not working, this may help you figure out where the problem is.
Finally, is your lamp post light working? A neighbor had the wiring fail on theirs, which caused several other problems.
Hope this helps.