Assuming no special state laws are involved, if you order online, the the SBR has to be transferred from one Type 07 FFL to a local Type 07 FFL on a Form 3. The Form 3 alone took almost 3 months the last time I did that, though I think times are much faster now. Since then, I don't order NFA stuff from out of state anymore unless I really want it and there are no other options.
When the SBR arrives, you'll go to your FFL and pay them for the transfer fees and fill out a Form 4. You send the Form 4 and $200 to the ATF and wait. Most of the wait time is because there are X many examiners and 50,000 forms. When they finally get to yours, they'll look at the paperwork - it isn't uncommon for paperwork to get sent back due to minor errors in filling it out or random examiner whimsy at this point. If the paperwork is OK, they'll mail you the stamp and you can then go to the FFL and take possession of your SBR.
A trust can make this process simpler in some ways since it reduces the amount of initial paperwork; but lately has been leading to a longer wait time because ATF examiners aren't lawyers and they aren't always great at reviewing trusts.