This is answered on my map. If you just want the access directions they are available separately further down on the downloads page. Harry, this isn't directed at you since I know you'll be parking outside the park border and portaging in, but to everyone else... remember it is STRICTLY ILLEGAL to operate an wheeled device on a non-designated road in Algonquin Park.
Oops, before I forget, here's the link to the map:
http://homepage.mac.com/canoecamping/Map/About_the_Map.html .