You will find that grouping you classroom library by author, topic (such as books about animals, school topics, etc.) or genre is one of the best ways to get your kids into your books . Within those groupings, you may have a way to identify books according to their DRA or AR level for yourself, as you mentioned. We want kids to choose books for two reasons–good fit books and books of interest. If we limit them to the “level” only, we may inadvertently limit their choice of books. Rather than have the kids be so concerned with the level, have them become good book choosers based on the “good fit” book lessons and “3 ways to read a book”. If we teach those lessons well, we hope that they will begin to pick appropriately leveled books for themselves. Of course, we can suggest books during our conferring and strategy group time.
Gail tells the story of one of her young students who, on a trip to the local library, didn’t check out any books because there were no “blue tub” books there. We don’t want that to happen!
You may want to view the video clip that Joan has about this topic. Here’s a link: http://thedailycafe.com/articles/classroom-library-design
Also, if you type “classroom library” into the search feature, you will see many examples of teachers at various levels.

Absolutely!! “Read the pictures” is so great for our first grade readers. They realize how much they can gain from non-fiction books besides reading the text. One personal example I recall. . . when my son was 4 and 5, we subscribed to ZooBooks magazine, which covered in great detail different animal species, and his favorite dinosaurs. Although he most definitely couldn’t read yet, he would pour over those and learn all kinds information about animal bone structure, muscle structure, habitats, etc. All of our kids need to be exposed to so much non-fiction text, and the science books you discuss are a perfect way to kids the kids interested and talking. Then they (or we) can begin to search for books at their reading level to help them see the connection between reading text and gaining knowledge.
Also, kids LOVE to “read” over and over books that you’ve read to them. Leaving them out for the kids to retell the story (another way of reading books) strengthens there interest and love for reading, as well.
Keep all the science books and let the kids love them!!

My school also uses both DRA and AR. What I ended up doing for my library is labeling all my books with the DRA level. I just put a rectangular label on the back cover (just for my reference). It was nice while conferring/moving around the room to glance quickly at the back cover and be able to see if a student was close to their level. None of my first graders paid any attention to the label. I did, later on in the year, point it out to a few of my higher student (reading at 3rd grade level and up) because they were having to spend a lot of shopping time looking for more advance books (since they are not the majority of my library). I also printed off circle labels that just said AR (but did not have the AR level) so my kids would know which of the books in the library were AR books.
Whatever you decided to do, I recommend checking out an app called “Level It.” It is free on iTunes and works on iPhones & iPads. Essentially, you just have to scan the barcode and the book info pops up (DRA, gle, lexile, gr). You can add books to your library (so you actually know what books you have!) and it even has a student check out system. I haven’t used that aspect of the app. Also check out Scholastic’s Website Book Wizard to get levels, etc.