I use the following Journal I picked up off Amazon:
http://www.amazon.com/gp/product/B00...?ie=UTF8&psc=1
It works well for us. I keep up with the Campground info, sites we would return to, distance and time to get there, etc...
Also use it to log maintenance, modifications, etc... to the RV so I can look back and see how many miles or time between certain maintenance items.
I am generally a computer nut and do everything on a computer, iPhone or something tech related, but in this case the Ole Paper and Pencil approach is nice for us and it just seems more interesting sitting down and glancing back through it to see where you have been, who you met, what Mods and Maintenance you did when, etc...