Kohl's Cares books are perfect at any time of the year. The classic Dr. Seuss books are a must-have for me! At $5, you cannot beat this. Another great read for 1st-3rd grade students is the Magic Treehouse series by Mary Pope Osborne. I have read these in the past, but this year I have done 3 book-clubs with this series. The kids adore the writing of Mary Pope Osborne, and more importantly there is a lot of history in the books, along with non-fiction facts.
Last but not least, my Mom bought Carter and Ella this book for Christmas. They also received the accompanying Snowman-Ken, which is the coolest thing ever. It is fun, whitty, and filled with holiday cheer. This book isn't specifically about Christmas, so it can be kept out all winter. Young readers turn into life-long-learners; happy reading little ones!