Joe,

I admit I'm not a waterfowler, but I'll try to help you out. The season dates for MD waterfowl has not be announced yet. You can get more info at http://www.dnr.state.md.us

As far as what guides, I have heard good things about Sean Mann who guides out of MD.
I'm sure he has a website, so you may want to do a search on his name. He may also be able to fill you in better on what dates the season may be for this year.

Hope this helps,

Slice