Written Directions
Starting from Salt Lake City, Head south down Redwood Road (UT-67). You'll follow this road south to its terminus in Elberta, Utah. Turn right onto Route 6 and follow it South West to Delta, where it meets Route 50. From Delta, you'll blast west across the Nevada desert until Route 50 terminates in Sacramento, California. From Sacramento, you can essentially follow the signs to San Francisco. I ended up taking I-80 into the city, but there are plenty of other ways to get there that are far less crowded.
Scenery
I'll divided this up by state, since there was just so much to see:UTAH: Early on, the route skirts the western edge of Utah Lake, which was gorgeous. I left early in the morning, so the sun was just coming up over the eastern mountains when I was riding alongside the lake. After that, UT-67 and route 6 both snake through some smaller mountain ranges and Ghost towns. Once you get past Delta, you'll be able to see the mountains that surround Great Basin National Park (a worthy side trip, if you've got the time).
Nevada - Route 50 has come to be known as the Loneliest Road in America. Stretching nearly 400 miles across Nevada, Route 50 connects only 5 tiny cities (more details to follow in the "Roadside Amenities" section). Nonetheless, it is without a doubt some of the most beautiful scenery I have ever ridden through. Nevada is in fact a series of small mountain ranges that run North-South. Route 50 bisects them all. You'll have spectacular views of mountains that appear on the horizon right up until you summit them and move on to the next range. Once you reach Carson City, Nevada, you'll head up and through a mountain pass which takes you around the souther end of Lake Tahoe.
CALIFORNIA: Starting right at the state line of California and Nevada, you'll start to descend down through the California side of Lake Tahoe. This part of the ride was probably the most fun. I'd estimate you take around 150 turns in a short 40 miles of windy mountain roads. It was especially nice to get out of the sun, since this part of Route 50 was shrouded by pine and eucalyptus, as well as loads of other local flora and fauna. After you get out of the mountains, it's a pretty straight shot into Sacramento. There's plenty of views of the Sierra Nevada, but the road certainly mellows out as you pass through Sacramento on the way to San Francisco.
Drive Enjoyment
An average of 3 Stars across the board. Roads near big cities are obviously more maintained than Route 50 in the middle of nowhere. However, Route 50 was a great road. No potholes, decent paint, just a lot of gravel, so look out, especially going through the mountains near Austin, Nevada.
Tourism Opportunities
As its name suggests, Route 50 is probably the most desolate road in the US. So gas, food and lodging are all few and very far between. However, the people in each town are all very friendly and helpful. I certainly recommend taking a spare gallon of gas with you.
Motorcycle Road Additional info
I was able to ride from Salt Lake to San Francisco in about 18 and a half hours, all in one day, on my Yamaha V-Star 650. If I was to do it again, probably would have made a stop in Austin for the night. Make sure you have both a spare gallon or two of gas, a windshield, and clothes that span the full spectrum of seasonal weather. I made the trip in May, and temperature ranged from low 80's to near freezing (it was actually snowing around Lake Tahoe and some other parts of Central Nevada). The wind was incredible as well. Ironically, Austin is the Land Sailing Capitol of the US, and the wind was around 30 MPH sustained when I passed through. It made me very happy to have a wind fairing to block some of the gusts.