Almost every year Comlara Park runs one canoe and kayak trip on the Mackinaw in May. It is through the park district so there is a fee but rentals (of canoes) are available and it's alot of fun. I will likely not attend but am posting this for any interested parties. It's also a great way to check out the Mac if you do not have your own boat. Beginners are welcome last I heard, and when I went on one of these paddles a few years ago they gave basic instruction in canoe strokes at the beginning of the paddle. At least then, people could also bring their own kayak. Anyone interested should double check on the above info if it relates to them.
Here is a link to their website - http://www.mcleancountyil.gov/index.aspx?nid=92
The number for registration is (309)[masked] I am not sure of the time of the paddle - the date is off the website.