Check here first, and do searches for your problems.
If you've troubleshooted to the point where you think you may have to call Verizon, here are some steps to make sure you don't brick your phone.
Before calling Verizon:
1.Rename all your .baks to plain .apk so they are installed again.
2. Make sure you uninstall anything you shouldn't have on your Droid (ex: Wifi Tether, Wired Tether) and finally unroot!
The reason you should do this, is if for whatever reason they want you to perform a factory reset, you don't brick your phone.
If you're not going to unroot:
If you don't feel like unrooting make sure that when they ask you to update to pretend like you're navigating and then say
"Your device is up to date! No update is necessary at this time."
If you have to send your phone in:
Factory reset, make sure you follow the steps above. I would do this just for your own privacy anyway.
This is all pretty much common sense, but under pressure, it's easy to forget these things. I'm sure there are other things to be added to this, if you think of anything.. let me know and I will add it. This just seems like a nice little guide to have in case you find yourself in a pickle.
Now that I think of it, this applies to all rooted phones, so you can move this thread to a more appropriate one.