The manual Field identification of the 50 most common plant families in temperate regions by Lena Struwe is available for download below.
(color pdf with images, 60 pages, (c) Lena Struwe)
Manual: Field identification of the 50 most common plant families in temperate regions (including agricultural, horticultural, and wild species) (4806 downloads )
Maura E High
This is such a useful and usable listing of plant families. I have been trying to understand mosses and grasses in particular, and this manual gives me the information to start with.