Part of the fun of geocaching is sharing our experiences with other geocachers. We traditionally have two ways to do that: hand written logs in the log book we find in the cache or with an online log. You can help geocachers provide hand written logs for your cache by providing an easy to use geocaching logbook.
When it comes to nanos you have almost no choice but to use a log sheet. For most other caches there are pre-made logbooks available. Even preform cache containers have a special logbook just for them.
I personally prefer logbooks that are spiral bound. I find these the easiest to use. I can flip to a page and then write my log without trying to keep the book open. At a certain size the spiral bound books are too big and the stapled variety are the only way to go.
If you want to really make an impression with your geocache you can use Rite in the Rain logbooks. These logbooks use a special paper the doesn’t get soggy. This can be very helpful even if it’s not raining. If your hands are wet from rain or snow and you handle a regular paper logbook you might get it wet. If you are using less than idea container you can at least use a RitR logbook to make it so future cachers can log their find.
Using quality materials not only shows your fellow cachers that you care about their experience it also means fewer maintenance runs for you. The cost of better materials can many times be made up for in the reduced amount of gas consumed performing maintenance runs.