I'm assuming you're in Ontario based on your email address. You will find many useful links in the 'Enviro Topics' section (in menu to the left) under 'Waste Management/Recycling' (look in a/ information by location - Ontario).
One of the links is to the Ontario Ministry of the Environment website (http://www.ene.gov.on.ca/) where you can find out about the many new changes to waste regulations in Ontario (including the requirement as of January 1, 2002, for all generators to register their hazardous wastes every year - see http://www.ene.gov.on.ca/envision/land/HWIN.htm)
Some hazardous wastes such as PCBs are federally regulated, therefore you might also be interested in the PCBs subsection in 'Enviro Topics'.
Companies who dispose of oil and hazardous waste can also be great sources of information. Click on 'Products and Services' in the menu to the left and search the Recycling and Waste categories (with Ontario in the location field) to identify some of the services in your area.
Note: Our Product and Service Directory is undergoing significant expansion, therefore you might want to check back periodically.