Hi
Shamsi!!
I live on the Northeast shore of Lake Tahoe and am happy to share some info about the Lake. It is an absolutely beautiful location (IMO) and I'm sure you'll enjoy your visit!!
(my avatar is my view from my deck)
...PM me if you want more info!!
WEBSITES. I recommend these:
http://www.tahoe.com/
http://www.visitinglaketahoe.com/
http://gocalifornia.about.com/od/calaketahoe/a/smart.htm (see related websites from this site)
http://en.wikipedia.org/wiki/Lake_Tahoe
If you're a big hiker/biker, check out the Tahoe Rim Trail:
http://www.tahoerimtrail.org/
And for North Lake Tahoe:
http://www.gotahoenorth.com/
LOCATION
Lake Tahoe is in the high Sierra Nevada mountains, with the lake at 6,200 ft. above sea level and mountain peaks up into the 10,000 ft. range. The border of California and Nevada is in the middle of the lake.
Reno is located about 35 minutes northeast of the lake and you'll likely take a scenic drive up State Route 431 (also called Mt. Rose Highway) to get to Incline Village and the North Shore. You can also reach it from Reno by taking I-80 West and exiting at Truckee (cute town with a few shops and restaurants) and taking either Rte 267-S or Rte 89-S to the lake.
It takes approximately 45-60 minutes to drive around the lake, following Rtes. 28 and 50.
Picture the lake as an oval clock and I'll hit the "major" towns (all are small though): Starting from the North Shore, Tahoe City, CA is at 10:00, Kings Beach, CA is at 11:30, Crystal Bay, NV is at 12:30 and Incline Village, NV is at 1:00. The eastern shore along Rte. 28 is super-scenic (picture clear turquoise water) and a sandy state beach (Sand Harbor). Further around the 'clock' is Stateline, NV at 4:00, South Lake Tahoe, CA at 6-7:00 and Emerald Bay (very picturesque) at 7:30 or so. There are many other towns you'll drive through.
I think the largest city around the lake is South Lake Tahoe, with about 12,000 people or so. Incline Village is next with about 9,000. All other towns are a few thousand or so.
The Nevada locations have casinos and they are smaller and less "flashy" than those in Reno and Las Vegas.
Other places you might want to see not on the Lake are Carson City, NV (south of Reno and east of the lake), Genoa, NV (old settlement and has the oldest tavern in NV), Virginia City, NV (touristy silver mine town where the 'mother lode' was found in the 1800s), Truckee, CA. Donner Lake, right outside of Truckee, is very small but also pretty. There's a CA state monument just outside of Truckee that tells the story of the Donner party.
WEATHER
What month are you visiting? From now through early June the weather will vary from lows in the 30s (nights) to highs in the 60s/70s (daytimes).
Into mid-late June throughout the summer months, it'll be 40s/50s at night and high 70s during the daytimes. It rarely rains during the summer months and is never humid. We get a TON of sunshine days and due to altitude, the sun seems hotter/stronger here. I can't stress enough to bring and use lots of sunblock!!!
The air is very dry too due to altitude. Bring lots of lipbalm and hand lotion. Your hair will dry quickly too.
Drink lots of water.
Sometimes some of our guests have experienced a bit of altitude sickness during their first 1-2 days here. If you feel light-headed, drink water and try not to exert yourself too much physically.
ACTIVITIES
Squaw Valley, CA is on 89-N between Tahoe City and Truckee and it has a nice resort, golf course, village with shops, a gondola to high camp (I don't know if it runs all summer but you can check on the website) and I think horseback riding. Check out
http://www.squawvalleyusa.com/
I think Northstar-at-Tahoe on Rte 267 between Kings Beach and Truckee may have horseback riding too.
http://www.northstarattahoe.com/
Heavenly in South Lake Tahoe also has a village with shops and a gondola too (again, check the website for operations)
http://www.skiheavenly.com/
There are tons of other outdoor activities people do year round. In the summer months, hiking, mountain biking, tennis, golf, kayaking in the lake, boating & water sports, and laying out on the beaches are very popular activities.
There are beaches all around the lake with bigger public sandy beaches in South Lake Tahoe, Tahoe City, Kings Beach and Sand Harbor State Park. There are smaller, beaches accessible by hiking in on the east and west shores.
Depending on when you come, you should be able to enjoy the beaches since it's very warm and sunny during the daytimes. The lake temps are cold and you might be able to swim at the shoreline. Going out in a boat for water sports (skiing, wakeboarding, kayaking, etc) may require a wetsuit, depending on how long you'll be in the water.
BBQs/picnics at the beaches are popular in the evenings, just bring warm layers.
There are golf courses in Incline Village, Stateline, South Lake Tahoe, on Rte 267 toward Truckee and
tons in Reno and the Carson City/Genoa/Minden area off the lake.
Outdoor concerts and shows are popular, especially in the Stateline casinos. Sand Harbor also has a summer outdoor Shakespeare play series in July and August.
Some of the websites I included above have more detail on specific outdoor activities and where to do them.
Have a great time!!!!!