Your tickets will include a separate bus ticket that looks like a regular amtrak ticket.Use this just as you would on the train. The driver will collect your ticket before or after you board.
You'll probably be riding with several other people making the same connection, along with others who are using the bus for their entire journey.
Book through Amtrak as if you were taking the train for the entire route, selecting your city pairs for where you want to go. They will take care of the rest.
For example, I often travel to Rockford, Illinios. I take the bus from Lansing to Battle Creek-Train to Chicago-Bus to Rockford.
I just book online LNS to RCK. I get 6 tickets in the mail for the round trip.
[This message has been edited by vincen47 (edited 01-28-2004).]