A how to article from "Nuts and Volts" Magazine. Good set of plans for your first coil.
http://www.nutsvolts.com/PDF_Files/tesla.pdf
Schematic for a HV High Current voltage doubler. Uses MOT's.
http://www.kwarc.org/bulletin/99-04/tech_corner.htm
Amplifier parts and kits, resistors and capacitors. Based in UK.
http://www.hificollective.co.uk
Some pictures, tips and construction details.
http://home.gallatinriver.net/mhammer/
Their construction and theory.
http://www.hills2.u-net.com/tesla/tccap.htm
Construction tips, including gaps, HAWG caps, Altair's MkII coil and pictures.
http://www.altair.org/tesla.htm
Download page, latest version of WINTESLA, excel spread sheets and GAPJIT programs.
http://www.classictesla.com/java/calculat.html
Provides information on tesla coils.
http://www.kronjaeger.com/hv/