I decided to concentrate on photographing trees, however, I can identify only few basic trees so at first I have to learn how to identify trees. There are many books on this topic. However, I'm looking for an electronic educational material or an electronic encyclopedia. I want to copy text and images into a Super Memo database for effective learning. I don't want to retype text and scan images from a paper book. I live in Czech Republic but I think a general guide or a North America guide to tree identification will be fine for me. The material must be in English.
Please, could anybody give me a hint? Than you very much.