Time to build your own guitar from the ground up? You should look through the parts supply catalogue books and check out the web for guitar parts... but where do you start? Try the sites listed below, and read this article, reproduced from 1800-instruments:
http://www.1800instruments.com/Archive/ghGear07.htm

WD Music Products http://www.wdmusicproducts.com/
one of the largest after market parts producers for electric guitar and bass

Stewart-MacDonald http://www.stewmac.com/
offers a complete line of hard-to-find tools, parts, and accessories for building and repairing stringed instruments

Warmoth http://www.warmoth.com/
Warmoth been crafting fine necks and bodies for over 18 years

Allparts http://www.allparts.com/
is another place to source your guitar building supplies

Exotic Woods http://www.exoticwoods.com/
the place to visit if you want to go the whole hog and actually start your guitar with a lump of wood

Jeanniw Custom Pickguards http://pweb.netcom.com/~pickg/pw1.htm
get that fancy pickguard of your dreams

Melvyn Hiscock’s "make your own guitar book"
Mailto: melvynh@globalnet.co.uk reference material to start you off in Luthiery

Mannmade Guitar Parts - everything but the wood
http://www.mannmadeusa.com/

1800-instruments
Australia's On-Line Guitar Shop: http://www.1800Instruments.com

See also:
http://www.guitarsite.com/makers.htm
http://www.guitarsite.com/makers2.htm
http://www.guitarsite.com/database/Makers/