Finding a store that sells sheet music and repairs instruments (on a local level) seems to have gotten harder over the years. In middle and high school I could name you at least 4 or 5 local places that offered those services, but not anymore.
For people who live in Northern Anne Arundel County, Rosso's is one of the more convenient locations to have your instruments fixed. They also offer a wide selection of sheet music for a variety of instruments.
With a staff knowledge in music, in addition to playing themselves, Rosso's also offers private lessons on pretty much any instrument (and has lists of teachers for those instruments they may not have instruments for).
In addition to that they also sell reeds and instruments and other items that are helpful to whatever you play at a reasonable price.