Backtracking, and getting lost is not only frustrating, but wastes time and gas, not to mention--it can put you in a foul mood--and you are doing this to have fun! Here are two sites that I'm sure you are all familiar with, but I'll list them anyway--just in case.
Google maps:
http://maps.google.com/
Mapquest:
http://www.mapquest.com/
These are nice tools for both route planning, and also to find out how far away a shop is from you. No bonus is going to pay for 100 miles of gas these days, so if you aren't sure of a distance--check it before applying for a shop.

