Ilford (many pages - look around the site)
http://www.ilfordphoto.com/applications/page.asp?n=16
Kodak: Teaching Basic Darkroom Techniques
http://www.kodak.com/global/en/consumer/education/lessonPlans/darkroom/fullCourse.shtml
Kodak: Darkroom Design for Amateur Photographers
http://wwwcaen.kodak.com/global/en/professional/support/techPubs/ak3/ak3.pdf
Kodak chemicals for processing black-and-white films and papers
http://www.kodak.com/global/en/professional/products/chemistry/filmBWmain.jhtml?pq-path=14024
Kodak FAQ (photo chemistry)
http://www.kodak.com/global/en/service/faqs/faq5026.shtml
Photography basics
http://www.tpub.com/content/photography/14209/