Find a hotel in Rockville/Bethesda/Germantown, one that has a shuttle that will take you to the Metro...From Metro to school, take a cab. That's just my advise, because hotels can be VERY expensive in downtown DC
I grew up in the area, but haven't been there in a while, but Germantown's a long way. If you find something ok price try to not go further out than Bethesda. Check out hostel's too, you may be able to stay a lot closer that way. Walking around Georgetown proper is easy, and its easy to Metro or Bus to other parts of town. What about the admissions office, do they have any deals with local hotels?
Georgetown is not on a subway and is very expensive. I recommend getting a hotel out of the main part of DC, then you can take the subway to either Rosslyn or Dupont, and there's a Georgetown shuttle bus to campus from these two metro stations.
I stayed at the Best Western Key Bridge Hotel about 2 weeks ago. It is pretty close to Georgetown (across the street from the Rosslyn Metro stop). The hotel room was fine, but the employees behind the desk were a bunch of idiots. I got the room over Expedia. It was around $95/night, but during Cherry Blossom Festival weekend, so prices may have dropped.
im at gtown now..FORGET THE D6 bus.
what you need to do is get to Dupont Circle Metro, or Rosslyn metro center, and take the "georgetown university shuttle" its FREE if you show the bus driver a letter showing you have an interview/business on campus, or if you dont have that its $1
but trust me....your best bet is to get a hotel close to a metro stop....ie Key bridge marriot, then walk the 2 blocks over to the metro, and catch the FREE shuttle
I went to G'Town for undergrad. My advice to you is to stay in Rosslyn across the river at either the Best Western that was mentioned above or at the Key Bridge Marriott. It's the least amount of hassle. But getting around D.C. really isn't a hassle if you know all the tricks. You can catch the GUTS bus in Rosslyn but I always seemed to miss it (they pretty much run only on the hour most of the time) and ended up having to take a cab (which is about $5-$8 bucks) or walking back to campus, so just a word of warning. It's still the most convienient place to stay though.
If you end up staying in Bethesda or somewhere else on the Red Line, go to Dupont Circle and take the GUTS bus or even better catch the G2 Metro bus at 20th and P Streets, right there at the Metro stop and across the street from the big CVS pharmacy, which is more reliable and frequent than the D6. It will take you right to the gates of the main campus. The med center is a short and pretty walk from there. Good luck!
I checked special rates on Expedia, hotels.com and travelocity and compared them all to be as close to GWU, but for less than $100. I was able to get a $79 rate for GWU Inn - one block from Foggy Bottom station to get to Rosslyn and take a short shuttle ride to Georgetown. If you prefer to walk, it will take 20 minutes.