This article covers what it means when two similar trains have multiple route numbers and how to book your trip.
This article on Amtrak Sleeper Cars is an excellent place for you to start your research on Amtrak long-distance trains' accommodations.
You can find a Viewliner roomette on Amtrak's eastern route trains. Although similar to Superliners, these roomettes are slightly different.
This page discusses 21 top questions I receive about rooms on Amtrak trains. The article covers various topics, including who shares your accommodation with, meals, and a suggested packing list.