(or stop picking all their books off the floor).
We're a family of readers- I met my husband at Chapters of all places! And while we love living across from the library for our own sake, one of our daughters likes to eat books and the other likes to rip them, so we just buy the girls their own books.
Aside from gifts, we buy most of their books at the dollar store or on the library discard cart for 50 cents. They now have so many books it's ridiculous, but I want to keep (and read) them all. We used to keep all the kids books on the shelf in my oldest daughter's room, but I'm sure you know how a toddler selects books. They pull them ALL off the shelf every time they decide to read. So EVERY night we had to put them all back.
Now all the kids books sit on 2 high shelves on a large bookcase in the baby's room where they can only be reached by an adult.
One shelf is small board books and another is storybooks and large board books. The anthologies and chapter books that I'm saving for when they get older are elsewhere.
In my 3 year old's room we have a dishpan bin (you can get them at the dollar store) filled with an assortment of board books and storybooks for her to enjoy. It's enough for variety at bedtime and when she feels like 'reading' on her own, but not so many that picking them all up isn't going to be a huge PITA.
I keep the bin in her room for 1-2 weeks and then change the books. To rotate the selection I take books from the left hand side of each shelf and put the ones from the bin back on the right. If there are any she's really attached to in the bin I keep them in for another round.
This system is great because there is less clean up, your child gets to use all their books, you don't get stuck reading the same ones 8 billion times and they get excited about the 'new' books every week.