I have a reading list for each child. I printed it out at donnayoung.org. I think it is a nice motivational tool. I also have a list of 'suggested' books for them to read so they don't miss some of the classics that we read as a child. Every once in a while I check one of the 'suggested' books out and hand it to them. So far they have loved them. For us it becomes part of our homeschool record and each keeps theirs in their binder for the year. I also keep my own lists for family read-alouds and for my younger son, but those are check lists of books I want to cover over the school year.
Yes, they can be extensive. My DD9 has become quite a bookworm, especially since I showed her how to look up and request things online.

Luckily we are at our library very regularly. We are doing a lot of learning through literature this year but I keep that seperate.