Hi!
In Poland You can buy maps almost in all bookshops. Also touristic maps. Route near Baltic Sea is not very intresting. You can watch some lighthouses and a lot of crowded beaches in summer.
Very intresting are sand dunes in Leba (
Sand dunes photos ). Intresting is Hel Spit(at the end of this is small pool with seals).
I strongly recommend castles (most of them are in south from Gdansk). Intresting are Malbork (
Malbork Castle ), Frombork, Gniew.
If You like cities Gdansk would be intresting place for You -
Gdansk webpage .
Write what You are intrested in (castles, architecture, beaches) and I can give detailed infromation.