S.G.
we lived there for some time, and my husband grew up there. Montgomery, Howard and Anne Arundel counties are the best as far as schools, though montgomery is a lot more expensive. And I'd stick to south, central and east of Howard county.
Ellicott City is really great and so much is popping up near there, and Columbia has so much as well (i LOVED the children's museum there and honestly preferred the mall there as opposed to the one in annapolis or the outlet mall in hanover)
We moved to texas so in comparison... Maryland (in all of the communities we lived in) never offered us that cozy neighborhood sense where everyone just gets along. Maryland is in between Baltimore and DC and everyone is pretty stressed, lots of traffic so I noticed it's a "hurry and get on with what you're doing" sort of place. not a "hi, how are you" type of place. I never made too many friends but if I were to recommend you find that kind of environment... it'd be Columbia. Lots of recreation, sports, shopping, museums and neighborhoods popping up by the minute. A lot of families moving there. Elicott City too but there are more yuppies there than Columbia.
There are playgroups in the area and you can find them on meetup.com. I had some good luck and a some bad luck.
Maryland is so gorgeous and I'm envious of you! the Fall is amazing and all the pumpkin patches you can go to and festivals for each season, and farms everywhere you can go pick your own yummies: http://www.pickyourown.org/MD.htm
And you're so close to DC and all their FREE museums as well as Baltimore with the science museum and aquairum!
good luck on the move! you'll love maryland!
texas has much friendlier people but i truly miss it.
=)