Just a quick update - there is also a doc on MetaLink that covers the integration elements in more detail. Keep in mind, though, that there are unfortunately omissions and errors within this doc - though I'm sure that later revisions will get better and better.
Here's the document details:
OracleŽ Transportation Management
Integrating Oracle Transportation Management with Oracle E-Business Suite
Release 11i
Part No. B31084-01
Thanks!
--Chris