Everyone has their favorite places on the web. These are mine. Some are caller references, some are where to go to dance.
Old Time Seattle - where to go in Seattle for old time jam sessions, square dances and more
Pour Parler - an annual gathering of folkdance teachers
Bubba Guitar - Bill Martin's wonderful website
Square Dance History - an amazing resource about all kinds of square dances
Northwest Folklife Festival - my favorite event of the year
Seattle Folklore Society - they put on many wonderful concerts and sponsor some great dances
Contra Dance Links - the most thorough and up-to-date list of where to dance contras, all over the world!
Ralph Page Legacy Dance Weekend Syllabi - An annual event for dancers, musicians and callers
Ceilidh Dances - party dances from the UK for all skill levels
Bands I recommend for your event:
Red Dog - Old time string band
Atlas String Band - more Seattle old time music