The only thing I can say is "so much to see-so little time".
If your estimated time for riding is 5 hours I would suggest you stay South of Boothbay peninsula. Shore road in Cape Elizabeth is a nice ride and you will pass Ft Williams Park and the Portland Head Light. Bailey Island is a good ride and you get to see the only cribstone bridge in the world. There are lots of good places to eat and spend the night in Freeport. If you go to Boothbay Hbr. take a side trip on Rt 96 (turn at the Irving Station) and ride out to the point, the views are great.
Here is another resource:
NER Best of New England This is probably the definitive guide to riding as it is compiled by motorcycle riders. Also check their forum for more info.
Have a great time.:bigsmiley11: