For Bethesda, do a search on here for USUHS. This was discussed pretty well before. There were alot of good suggestions on where to rent and not rent.
As far as housing, you do not get priority based on rank. You do get priority based on need. A single physician without dependents is not as pressed as a single E4 with 4+ kids. The wait is definitely long and depending on where you're placed not worth the wait. Andrews was in the process of refurbishing some of their old housing. I wouldn't recommend it.
I would say downtown Silver Spring would be a good area. They are pumping alot of money into that area. You are in between WRAMC and NNMC. Not sure how much that'll matter since they BRAC'd WRAMC. It isn't cheap to live here in Maryland. There are still some areas of DC that haven't flipped completely so you could find a good deal on a home. The caveat to that is "haven't flipped" means these areas are still rough to live in. By rough I mean drugs & ho's. 😎