Graham,
Depending on your actual schedule, May 25 at 2 PM is the rehearsal day for the Blue Angels over the Severn and Annapolis Harbor. They will do their show on May 26 for the Naval Academy graduation ceremonies. A great show, but the water will be covered in boats. If you want to stop close to Annapolis but not deal with the crowds, the Magothy River has a lot to recommend it, and I can connect you w/ folks there. Sadly, I'm stuck in CT, but I sailed a lot of the Magothy Wednesday night races on friends' boats and a word in the right ear would have you on the starting line. My big boat was kept up Mill Creek, south of the bridge and closer to Annapolis, and it has nice protected anchorage and a killer creekside crab house.
I have a ton of good stops for you from Baltimore down to the Mobjack Bay, but as a starter, this month's Spinsheet magazine has a good article on the largest of the Eastern Shore rivers, the Choptank River. You can read Spinsheet online at spinsheet.com.
Coming south past Baltimore, be aware of several shoals and bumps just north of the Chesapeake Bay Bridge. While none of them are shallow enough to fret Carlita's draft, the cross chop that can build up on them is wicked, and if a big ship is heading out of the Patapsco River, its wake can build up on those shoals and really surprise one.
Further south, Solomons, MD on the Patuxent River has a wonderful harbor, excellent marinas, restaurants and good anchorage. Jutland Creek, off of the Potomac, just inside Pt. Lookout, is a good anchorage and marinas are right there too. It sheltered me for a 2 day blow when I just had enough of beating myself up on a passage south.