wrhk43 - The info's out there on what needs to be engraved on the receiver and also about what needs to be on the paperwork. It's pretty simple really. The only thing I found tricky when building an SBR (using an existing receiver) was how to calculate the OAL ( I later found this info also). Here's an example of trust engraving (and no, that's not my trust, but it looks just like that with a different trust name):
Henry Trust
Albuquerque, NM
What else do you want to know? I've answered a lot of questions (as have others) in the main threads on this subject at this website. Ask away, there's plenty of knowledge here.
Now if you're buying an existing SBR or suppressor, no engraving is necessary. I'm sure your FFL/SOT will help you with the paperwork. I can tell you what to send in if you don't already know. Then you WAIT for a lot of months (but my last 2 suppressors and SBR ONLY took about 5 mos!) So if you want one to hunt with this fall, start now.