Call Amtrak at 1-800-USA-RAIL or visit Amtrak's web site in the "Resources" section below. On the web site, you can book your train reservations via Amtrak's Fare Finder. You can also navigate the site if you have a PDA, Blackberry or other handheld device.
If you ordered your tickets online or by phone, pick them up at a ticket agent or at one of the Quik-Trak kiosks that can be found at many Amtrak locations (you'll need to enter your reservation number). If you've booked your trip far in advance, you can also request that your tickets be mailed to you.
The Coast Starlight, San Joaquin and Pacific Surfliner all make this trip. The Coast Starlight is the only route that does not involve a connecting bus ride, and it is the only train with a dining car.