For a British perspective on sweet peas, look to the custodian of the national sweet pea collection, Roger Parsons at Sweet Pea Seeds Online. Among the Articles of Interest on this Web site is information on using sweet peas in bouquets, sweet pea history, and types of sweet peas. There is also a "How to Grow" page and links.
For more of the fascinating history of sweet peas, plus some great trivia and quotes, visit the Owl's Acre Sweet Peas. Of course, there is also information on sweet peas from the Royal Horticultural Society and from the National Sweet Pea Society.
On this side of the Atlantic, Fragrant Garden Nursery, a mail-order company specializing in sweet pea seed, offers the most detailed information on growing sweet peas. Their web site also gives you a chance to see color photos of many varieties. Enchanting Sweet Peas, another sweet-pea-only company, offers Seven Grower's Secrets: How to Grow Unusually Beautiful Sweet Peas.
And sweet peas are one of Renee Shepherd's specialties. Sweet Peas; Sowing Seeds Directly Into the Garden will help ensure success.
The Sweet Pea Book
If you require your sweet peas to be perfumed as well as beautiful, you'll enjoy curling up with The Sweet Pea Book by Graham Rice (Timber Press, 2003; $19.95). You'll find a bit of history, descriptions of the most fragrant varieties, explanations of different flower types, and design ideas for growing these lovelies.