I would either invest in a guide book like Graeme suggested or just check out one of the gay free papers when you get to a city(record shops are good places to find them), every city seems to have them and they are generally a really good guide on events going on as well as a lot of the pubs and bars. other than that the web is all ways a reliable and easy way to find what's on where, just google (name of city) gay guide and you'll generally come up with a couple of web pages which at the very least are a good place to start.
I've done a fair bit of travel round the world and had a lot of hilarious nights and one thing I'd suggest is trying to find the smaller local places, ive found is the meat markets of the big clubs are the same everywhere really, and I've met a lot more interesting people and had a lot more fun and random nights going to the smaller places and just going with the flow. Heh met more interesting AND cute boys at the smaller places as well instead of just the latter which seem to haunt the clubs a bit world over.
Also even if there's not a gay village gay bars tend to be in relative proximity to each other so if you find one wonder around and you'll probably find a few more, oh and keep an open mind. Heh i remember once wondering into a bondage club by accident in London and spending most of the night talking to a Master before he had to stop and go 'punish' his 'slave'.
Basicly the best bet is treating it like you do the rest of your travels, keep an open mind, try and be as friendly as possible go with the flow and you'll have an awesome time.