I work in the Delaware area but if you need help from a realtor, let me know @ firstname.lastname@example.org and I will find a realtor for you that works in the area.
Ditto to the reply from Emily, but since I work with residential sales in Cambridge, Massachusetts and got your request I thought I'd confirm that you meant MD, not MA. Craig's list is your best bet no matter what for rentals almost anywhere.
Trulia doesn't list rental homes - only residential homes for sale. Perhaps you'll have some luck if you check out the link below to Craiglist in Maryland.
Customer Service Representative