Most of the time, my pre-ride breakfast is Eggo nutri-grain waffles. Lots of carbs, not too heavy, not a lot of fiber to cause GI issues.
For longer rides, I bring 1 packet of gu per 10 miles, plus 1 for good luck (I usually can't tolerate solid food during a ride.). For rides longer than 2 hours, I have one 20 oz. bottle of gatorade, otherwise I drink water. For really long rides, I have 2 bottles of gatorade plus water.
I read Nancy Clark's Sports Nutrition Guidebook back in 2001, and used that as a starting point for figuring out what and how much to eat.
Immediately post-ride, I drink orange juice. Other post-ride nutrition varies depending on where I am (home or in a parking lot somewhere), but I try to lean towards a mix of carbs and protein with not too much fat. Smoothies, cereal with milk, or a cheese sandwich are good. After a really hard ride I'll have Kashi Heart to Heart cereal, which has lots of antioxidants.
If I ride 60 miles or more, I treat myself to dinner at Five Guys (awesome cheeseburgers and fries).
By the way, re: Hammergel or other gel for breakfast, I used to know a guy who did lots of inline skating. For his pre-skate breakfast, he put vanilla gu in his coffee.

