Iguanas, unlike most reptiles, are actually vegetarians. Back when I had an iguana, I had a 'salad' recipe for him. Sadly, I can't find it right this second, but I know it contained acorn squash (or pumpkin), some sort of berry, greens (collard greens, I think) - all fresh and run through a food processor. The alfalfa (usually found in the rabbit food section of the store) was ground up, and added at the end.
I would make a big batch of salad and freeze it into ice trays, pulling out two cubes each day for a meal.
For an occasional treat, he would get a leaf or two of spinach - it is too high in calcium for the regular diet, though. Berries are a fun treat, too.
The biggest thing is you need a good enclosure for him, with appropriate lighting and heating, as well as (ideally) a pool of water for him.
Iguanas can be great pets, but they are by no means low maintenance. Consider carefully.
| 
