Reno is a great place to use as home base. The closest mtn will be Mount Rose (20 min), but that's a pretty small resort. For intermediate, I'd recommend Northstar, Alpine, Squaw and Sugar Bowl. A little more detail about the hills.
Northstar (35 min) is Tahoe's ultimate intermediate, family friendly mountain. Their runs are well groomed, there isn't any crazy steep terrain, plenty of carved out trails, can do decently long top to mid-mountain runs and in general, you have to look hard to find any moguls at Northstar. The main disadvantage of Northstar is they only have 1 single lift that takes you to the top so 15 minute lift lines are almost normal on weekends. If you can do Northstar on a weekday, you'll love it. Check out: Anything on the front left (looking at a train map) side of the mountain.
Alpine (40 min) is a mid-size/small mountian in Tahoe that still has a very local feel to it. There isn't a ton of development or a snazzy new village, just lifts and great terrain. Alpine will have slightly more difficult terrain (steeper and not as well groomed) than Northstar, and its style is more ski to the bottom of the lift, rather than ski the trail, giving you more room to roam. Apline has 3 great bowls, 2 of which are rated intermediate, for people to rip through. Alpine is more wide than tall. Of the 4 resorts, I think Apline might offer the least amount of intermediate terrain. Check out Summit Six chair, Lake View chair, and Sun Bowl
Squaw (35min), the ultimate Tahoe resort. Squaw has the most actual skiable acers in Tahoe and is home to some of the most difficult terrain. However, for an intermediate, Squaw offers TONS of options, open bowls, long runs (think top to bottom is 3.2 miles), no lift line crowds on weekends (except maybe Shirley Lake), multiple mid-mountain bases and pretty good grooming. Like Apline, Squaw is also more ski to the bottom of the chair style, rather than follow a trail. Squaw is both wide and tall, so there is a lot of area to explore. A must ski on your trip. Check out: Squaw One lift, Siberra lift & bowl, Shirley Lake lift and late in the afternoon when the main mountain gets too many people, head to Red Dog & Squaw Creek.
Sugar Bowl (45 min) is a great mid-size mountain spread out across 3 or 4 peaks. Decent grooming, intermediate terrain won't be as steep as Squaw or Alpine, runs will be as long as Alpine's, and lots of intermediate terrain to choose from.
All Tahoe resorts allow snowboarding, so your buddy will be fine, and tell him to keep his speed up when you hit some flat sections. All the resorts, except for Northstar will have small flat sections, but nothing horrible.
As for driving when its dumping, you should be able to get to Alpine, Squaw and Northstar without chains in all but the worst conditions. If chains are required pick some up in Reno and practice putting them on in the driveway/garage. I believe Squaw offers a free shuttle from Reno, Sugar Bowl offers a free shuttle from Trukee.
If you're flying into San Francisco, San Jose or Oakland and driving up to Reno, check out www.slidingonthecheap.com
for all the discount lift ticket info. If you're flying directly into Reno, I'd recommend buying tickets from people on Craigslist.org and having them mail you the tickets. Its pure based on trust and honor system, so be careful.
Have a great trip