If you need a book that has an interesting way of teaching about trees - just by looking at their shape, bark, etc. - then Winter Trees by Carole Gerber might be the one for you. This is really a good look at the "winter shape" of trees. Leslie Evans has done a wonderful job of illustrating this book - I think kids will find it interesting and a fun way to learn. I enjoy tree indentification and this one intrigues me - I guess I hadn't thought of how you can identify trees even in the winter without the leaves!!