I've not used the corn gluten meal yet (DH keeps beating me to the lawn with his beloved chemicals - I'm on to his scheme, though, and don't think he'll get me this year
). FWIW, my neighbor uses it, and he said that it does a much better job keeping your lawn weed free than getting rid of well-established weeds. He said that after many years of trying to get rid of his weeds with CGM (and he does like a perfect lawn, so keep that in mind), he used chemicals for 1 year to get rid of all of the weeds, and then switched to the CGM after, and was really happy with the results.
As a fall fertilizer, I've used rabbit food (the alfalfa pellets). It adds a lot of organic matter to the soil, and is relatively inexpensive if you get it from a feed store.