The best way to find clubs here is through word of mouth and personal preference. I had to go to a buch of shitty clubs before I found one that I liked. I like Ginger, had a good time there. It's at Granville and Davie.
Lotus, Richards on richards (from time to time), the Commodore (for big blow out bashes or big dj's from time to time) are some of the sports to check.
Ginger has been bringing in some quality dj's as well (saturday night's are the night).
Bar None and a few smaller joints have some small decent nights happening from time to time and one-offs with guest dj's (fred everything was in town not all that long ago).
keep your ear to the ground, check out the downtown record shops for flyers and info, and there is also a good website that escapes me right now, but has loads of info on it. i'll post it when i remember what it is!