I head up from SF almost every weekend in the winter. From walnut creek, i might take the 4 to stockton and avoid the SF-Sacto traffic. plan on 2:45-3 hours, with traffic adding as much as 2 hrs on friday after work. As far as places to ski/stay, it really depends on what you like to ski
Kirkwood - up to 45 minutes from south lake, but some of the best terrain in tahoe. not much to offer in terms of cheap lodging, though
Heavenly - too crowded and spread over two states. not much vertical
Squaw - great mountain, but this is the first year they have had decent season pass prices, so it will be very crowded
Lots of smaller mountains, also. Mt. rose is a personal favorite. Snow is very heavy here, light powder days are rare.