Unfortunately, neither of us possess a memory like a steal trap. In fact mine is more like a sieve, with everything slipping out through the holes. Since we can't rely on our faulty memories, we decided to create and keep a camping log.
I found what I needed among my old school supplies: a 3 ring binder and plastic sleeves. For each new campground we stay at, I slip all kinds of reference materials into sleeves. We walk (or drive) through the campground and circle our favorite campsites and make note of the location of water fill stations and other points of interest. I include trail maps, fishing/hiking guides, and brochures for the area, and then in the first few days after our trip (so it's still fresh in my mind) I type up a brief report with sections on the specific campsite we stayed in, the campgrounds as a whole, and the area in general.
The log has already come in handy, as I struggle to separate details of campgrounds we stayed at earlier THIS summer (see, I told you I was bad). And no matter how many times I flip through the binder I don't have to worry about ripping the pages as they are safely protected in their sleeves.