I can see that an unidentified page would be a good introduction to a type of plant Paul.
If you go to the Plants tab then search for a genus, then they do list alphabetically with a photo in the column if there is one. There's thousands of Hosta cultivars, I once used to check them out on a hosta site.
http://garden.org/plants/brows...
I can see that a general introduction to a type of plant would be a good idea but with an example of all types of plants for those who are totally lost in the plant world! I wonder if that is possible, I wonder if Dave could do magic and link a single typical example of all the genera listed so they show in one place. That might be a very tall order though! It's not always that simple as species and hybrids within a genera can vary a great deal so as to not be reconised as belonging in the same genus.
Maybe an introduction to include a typical example in each family would be good for newcomers to plants, with notes on what a family, genus, species, cultivar or variety or form is. A link from each photo to the family might also be a good thing with sublinks to genera but I have a feeling that would be a lot of work.