Otto,
If you're looking for an area with all of the tourist things - t-shirt shops, mini golf, ice cream stands, fried seafood, etc. - look in Falmouth, Barnstable (mainly Hyannis), Dennis and Yarmouth. Although some feel these towns are too built up, if you've got an active family that needs to stay busy, this is the area. If you're looking for more peace and quiet, the outer Cape - Eastham, Orleans, Truro, Wellfleet - might be for you. Harwich and Chatham are kind of "in between" as far as tourist stuff and quiet.
All these towns have ramps, some public, some resident-only. Check this site for public access once you've determined a location -
http://www.state.ma.us/dfwele/PAB/pab_table2.htm