If you have a Laptop PC...
In addition to paper maps, if you already own a Laptop PC, just get ahold of Microsoft Streets & Trips for those up-close maps of areas not covered by most traditional paper maps (small towns, etc.). Being that it is a digital map, it's also highly dynamic as far as calculating distances and automatic route finding.
In Car GPS is okay, but if you have a laptop computer you can save some money by just picking up Streets & Trips or comprable software.
Just a thought.
-Brad