It's not hard to put a hitch on a golf. You ccan buy them from most part stores. But they can't handle too much weight. What were you gonna tow with it? If it's just a small trailer then that shouldn't be a problem. But i'm not sure i'd wanna tow a boat or somthing with one. But it's your car so you be the judge. I don't think there is an exact number of what it can handle. But maybe somone knows from experience.
When I got mine, they said the tow capacity was equivilent to two jetskis... but thats a 1.8T MkIV, so this information is almost completely irrelevant. Call the service department, they can tell you the tow rating.