Lighting changes are generally easy to make, low cost and depending on the type of business, can reduce energy costs by up to 50 per cent.
Before you replace existing lighting get hold of a light meter and check if you can make more use of natural light and remove unnecessary lighting (delamping).(You can get a light/lux meter for about $50 – just google them)
There is tonnes of great info on the web in regards to energy efficient lighting but the Sustainability Victoria Fact Sheet covers most bases. Click on the link below to have a look:
http://www.seav.vic.gov.au/manufacturing/sustainable_manufacturing/resource.asp?action=show_resource&resourcetype=2&resourceid=34