Below is a collection of boomerang related websites.
If you want to check out just one, I highly recommend the one from Pierre Kutek www.kutek.net. It has a great page with boomerang sellers, links to galleries and more than 1000 boomerang plans.

If I missed yours, just drop me an email.
Enjoy!

Portals:

Website for Long Distance Boomerangs (www.baggressive.com/)
(French) BoomerangPassion
(German) Boomerang Portal, (www.bumerangs.de)
Portugees Boomerang Portal (www.bumerangue.com)
Portugees Boomerang Portal (www.boomerangs.com.br)
Boomerang Webring

Other:
Adam Carroll's Realboomerangs website (Maker of my favourite Ayr!Back online with new line up)
Kendall Davis, great craftsman (www.kendalldavis.us)

John Cryderman Canada (WorldGreatBoomerangs)
BlueStar Boomerangs by Volker Behrens
LMI and Fox Rangs from France
(German) Boomerang School (www.bumerangschule.de)
Kutek, 1000+ boomplans, boom sellers list, great stuff (www.kutek.net)
Dave Hendricks, rangs veteran and info (www.bvdrangs.com)
Ted Bailey website (www.flight-toys.com)
Lots of rangs, lots of info (www.Boomerangs.com.)
Greg Courtney, Great picture webalbums and info about boomerangs
Alberto from Argentine, Gallery of his craftmanship
Hungary Website, some video of indoor booms
(Dutch) website about boomerangs (www.boemerangman.nl)
Rich Harrison (theboomerangman.com)
Boomerang explained (www.howstuffworks.com)
French Website with Outtakes from Bagdad cafe
Long distance and competition rangs from William Watts
Aboriginal Steve's Boomerang Page

Throwing instructions:

Colorado Boomerangs, Great boomerangs from US
Boomerangs and throw instructions (www.boomerangfan.com)
Site from Mike Gel(www.gel-boomerang.com)
Bob Burwell, great Boomsmith from Queensland