I set up with my canon 7D, using a 60mm macro lens and an inexpensive yet robust Neeweer Ring Flash. I reviewed the Neeweer a few blog posts ago (http://www.chriskiezphotography.com/1/post/2012/02/macro-ring-flash-led-light-by-neewer.html). Its a no-frills unit; you can't dial down the power of the LCD lights, and I'm sure the LCD lights used are not 100% natural daylight output like on the $500 models, but this one was $30.00 and does an acceptable job in my opinion.
Why use a ring flash with a macro lens?
A ring flash sits at the end of your lens, attached by an adapter ring which the light housing then slots onto. The flash is made of a series of small LED light bulbs arrayed in a circle, so as to provide a ring of consistent light output around your lens (see bottom of this blog for a picture of the Neeweer ring flash).