If you are already familiar with all the concepts, you probably won't gain that much from these, but for those just starting up, I think it can provide a great overview of what the system can do.
You can start by reviewing the presentation one of my colleagues did a while back.
For a more in depth look, you can go through the TMS learning course (note it is based on AX 2012 R3, but the functionality is largely still the same in the latest release):
A couple more learning videos are available through the below link:
Transportation management implementation guide and white papers available can be found through our SCM team blog posts:
And, finally, we have a permanent page on doc.microsoft.com, that you can access through the below link. This is where most of the upcoming functional changes and updates will be communicated going forward.
And, of course, if you have further questions after this, please reach out, so we can connect you with the right people to help.