Thanks everyone.. I will be in a roomette on SWC from Chicago to L.A. I am both excited and nervous at the same time.
That will be a luxurious experience compared to a Metra train.
(1) Get to Chicago Union Station earlier than you would arrive to catch a Metra train; Amtrak boards futher in advance of departure. Be sure to use the Metropolitan Lounge while waiting -- you're entitled to do so because you have a roomette. The regular waiting areas can get extremely crowded, but the Metropolitan Lounge is comfy. They will often board sleeper passengers directly from the Metropolitan Lounge. Once they march you out to the train, the sleeper attendants will generally be standing at the doors of the cars. One of them will be for your sleeper car -- if you show your ticket to the wrong one, they'll point you to the right one.
(2) You'll have "e-tickets" which means you can print out as many copies of the ticket as you want. Be sure to bring at least one copy!
(3) Meals in the diner are included with your sleeper ticket price. Be sure to ask *when* the diner meals are, since if you miss the window (by, for example, sleeping through breakfast-time) you will miss the meal. The times seem to vary by train and I don't remember the specific times on the Southwest Chief. Someone will come through to take reservations for lunch and dinner; if you are somehow not in the room when they take reservations, be sure to go to the diner to make a reservation. Breakfast is "show up and eat".
(4) The sleeper car attendant should make up your bed for you when you ask -- a popular time is while you are at dinner -- and should return the room to "daytime mode" when you ask -- a popular time is when you are at breakfast. People often tip the sleeper attendants, but this is a matter of discretion (there is no standard rate). Since you've never ridden in a sleeper before, let the sleeper car attendant know this and they'll probably tell you where the restrooms are, how all the buttons in the room work, etc.
(5) Be sure to visit the Sightseer Lounge. Many people think the most scenic part of the route is the "Raton Pass" between Colorado and New Mexico.
(6) When you get to Los Angeles, spend some time looking at historic LA Union Station if you can; it's worth it.
You'll (probably) love roomette travel; it's luxurious compared to riding a Metra train. Unless you've been on an ocean cruise liner or cruise train, you've probably never travelled at this level of luxury. You'll love the trip.