This online catalog has a good search engine to help you find bulbs based on price, color, bloom time, culture, or type. Not only is the selection good, but each entry in the catalog is accompanied by a color photo.
For those of you who go gaga over Hostas and hardy Geraniums, check out this site! Photographs abound for these two genera, graciously accompanied by descriptive text. Other information is available (mostly textual) for Astilbe, various ferns, and Primula.
This site offers not only useful gardening tips and links to some really cool gardening sites, but it also includes a free monthly news letter covering a wide range of topics. The garden nursery links are particularly good, and well worth the visit for these alone.
Dr. Leonard Perry presents his view of the perennial world online. His pages provide links to perennial resources on the Internet as well as a perennial of the month, photographs, and a quiz to test your perennial "savviness.
This nursery has all kinds of information about foxgloves, coneflowers, Jacob's ladder, and other species as well as links galore to various references on the Web. And of course, they sell plants too!