Hey Phoenix! Okay, the folks above have mentioned some helpful trails for your husband - NW Branch, NE Branch and Sligo. The best online map I know of for local trails is at bikewashington.org. Sligo is an old school trail and is 5 feet wide and kind of serpentine but fun. These trails should be able to help most of the way. From Hyattsville I would think of riding the roads to connect with Sligo Creek but you should check out the maps for your specific location. Also you can get the ADC Bike map from most bike shops to find friendlier roads for commuting.
Now your husband if he works normal hours will not be able to use the Metro train which does not permit cyclist during rush hour - however the local buses all have bike racks. You can get bus schedules at wmata.com and by calling 202-637-7000. There are buses that go directly between Silver Spring and West Hyattsville. There have been days where I bike in, but use public transit back without problem.
Peace to you and your husband.