Depends on what you're used to.
First off, get a backrest and Airhawk or some other seat pad. You should also look into a cramp buster or throttle lock of some type. These will add several hours of riding to your day. The bike will be just fine on a 3k mile trip. Just change the oil, check tires, etc. beforehand
So far as riding mileage, that is up to your personal preference. Personally 350 miles is a nice day of riding for me. I haven't done it for a while, but with my current set up, 500 miles a day would be comfortable. However some can do 700+ or even 1k in a day.
I like music when I ride. However, A long distance riding friend said whatever you do, DON'T get audio books. They're known in the LD riding community to put you to sleep. Not my cup of tea, just passing on the info. Speaking of tea, limit fluid intake when its cold (I keep hard candy handy, just to keep my mouth wet) or you'll be stopping every hour for bathroom brakes. If its hot, you'll perspire a lot of moisture, so keep hydrated.
The Cannonball rally people (
http://www.scootercannonball.com/) say your first couple days will be your best, riding mileage wise. You should plan on 80% or less on subsequent days due to fatigue. But I doubt many can ride the kind of days these guys do. Check out their forum page. Lots of good information there.
If you get all the out here, be sure to get down to Monteray, Big Sur and Ca coastline a bit. It's generally regarded as one of the best riding routes in the world.
Hope you have a great trip! You're gonna love San Fransisco. It's one of my favorite cities.