I always save my maps in the galaxy folder in the game directory (along with all the other scenarios.
Mine are all located at: "C:\Program Files\Stardock\TotalGaming\Sins of a Solar Empire\Galaxy\mapname.galaxy" for example.
Many do the error of putting them into the galaxy folder in the user dir, where the in-game editor puts its maps, this doesn't seem to work though. (instant defeat at map load)
As for ships and races, I don't think this is possible with the Galaxy Forge alone, you'll need the mod tools and some serious know-how to put something like that together.
You could also have consulted the readme's and tutorials around, I'm pretty sure they contained the answer you were looking for, instead of making your own thread and continously bumping it...
