The Standard Model - http://arxiv.org/abs/hep-ph/9812242 Lectures at the graduate and post-graduate level providing an introduction to the basic aspects of the Standard Model. Available in postscript and PDF formats only.
Particle Physics - http://blueflag.phys.yorku.ca/yhep/main.html An introduction. For Standard Model information, click on the third item in the index. The site provides brief descriptions of a variety of particle physics topics.
Particle Adventure's Standard Model - http://particleadventure.org/particleadventure/frameless/standard_model.html A popularization of the physics of the standard model. (The website is somewhat slow unless one has a broadband connection).
Information on the Standard Model and a Possible Difficulty - http://www.jupiterscientific.org/sciinfo/smtrouble.html Introduction to the Standard Model. The site also contains links to other topics such as neutrinos and electroweak-symmetry-breaking/mass-generation.
Help build the largest human-edited
directory on the web.