RV Parks directory

We are brand new to RVing. Bought our Class C, but haven't hit the road yet. I was wondering if anyone had any input on the 2006 Trailer Life RV Parks, Campgrounds & Services Directory and/or CD's? Are they a good investment? Is there a better directory? Thanks.
RV Parks directory

We use that one AND Woodall's book. We alternately update each one. They give you some idea as to the facilities available at a park with some measure of the reviewer's opinion of the park. We use the books on the road, but we use them more while we are planning a trip.

One planning aid we use more is Good Sam's trip planner. You can plan for different legs of a trip and get times and distances and Good Sam parks along the way.

I see the CD directory as a bit of a pain and would stick with the book style.

The more we travel, I can see how we use some of these aids less, but I don't see a time when they won't be needed. For the investment, they are very useful.