I split my nonfiction up more. Previously I had a science basket and a social studies basket. That was okay but the books went everywhere. Now I split the science into three baskets: plants, animals, and other. I also made a basket for all the National Geographic Kids books. For social studies, I made a basket for people and places and a basket for holidays and history. I hope that by dividing the books into narrower concepts for each basket that the kids will have an easier time remembering which basket the books came from.
Part of my library is arranged by genre. I didn't have enough baskets last year, so this year I added two more realistic fiction baskets, two more fantasy baskets, and another mystery basket. I also added a basket for graphic novels and a special basket for Bluebonnet books.
Kids love magazines. My problem was that I had so many magazines that it would take over ten baskets just to hold each magazine. I decided to group them. One basket is all Boys Life. Another basket is Ranger Rick and Ranger Rick Jr. The next basket has science magazines like Ask, Odyssey, and Owl. Another basket has National Geographic Kids. The last basket has American Girl and Discovery Girl issues. The green shelf has other assorted materials (dry erase markers, scissors, notebook paper, erasers, magnetic letters, etc.) but can be emptied out and used for book baskets if needed.
The majority of my classroom library is arranged by series or author. All of the books on these shelves are by author or by series. The series that are more popular (Goosebumps, My Weird School, or Geronimo Stilton) have multiple baskets. I try to arrange the baskets differently throughout the year. As we start the year, I put the less challenging books like Ready, Freddy or Judy Moody at the top of the shelves so they will get plenty of action. As the year goes on and the kids become more confident independent readers, I put the more challenging books toward the top. Typically the top shelves get shopped first.
While I would have liked to put all the books together in one place in the room, it's just not possible without blocking part of the room. I want to be able to see all the kids while I am at the group table in the back. So I kept the section of the library by author and series up front and put the other sections with baskets by genre in the back of the room.