You will have a great winter in Nelson. If you have a car, get a pass to Red and Whitewater. If without a car, hitch to WW.
As Dano posted, WW has some of the best snow in Canada (Powder King is also known for great snow, but it is really small and out of the way). It has great trees, and a good vibe. The restaurant is also very good (seriously). Whitewater is famous for its backcountry access, so get some gear, take the courses, and make friends.
Red has the best tree skiing of any hills I have visited. Unlike Pete, I have had great luck with Red. Every time I go, it dumps. Perhaps that is why I rank it (tied with Snowbird) as my favorite hill.
It is really low in elevation though, so rain can be an issue.
If you go to Fernie, overnight it. It is doable as a daytrip, but the driving can be rough (especially the creston-salmo highway). If you go to Fernie, check out Castle on the other side of the divide (about an hour and a half away). I haven't skied Kimberly, but my impressions have matched Pete's...there are more interesting options in this area.
Access to Revy isn't too terrible from Nelson either. Again, it would be an overnighter, but the drive is reasonable (need to catch a ferry but no passes) despite the fact that is definitely backwoods travel.