I like staying at the Ridge, which is a timeshare/condo you can rent by the week, as opposed to one of the casino/hotels at Stateline..

http://www.ridgetahoeresort.com/

The Rafting trip down the river in Tahoe City is a must do. It is very calm, except for the last half mile or so, where it gets a bit exciting..

http://www.truckeeriverrafting.com/index.php

Don't miss Virginia City, and a trip to the Bucket O' Blood..

http://bucketofbloodsaloonvc.com/home.htm