My DD went at 9 months and LOVED the Charactors. It all really depends on your child. The charactors will be willing to take picture with you little one with you holding them. I don't recall any of them picking my DD up. We did crystal place with Pooh, Play and Dine at DHS, and Dinner at the land with Mickey for the interaction with charactors. Next year we will add Chef Mickey,instead of play and Dine.
You know your child best judge how comfortable they are with the charactors and keep that in mind. My DD (18months) loves them, has never been afried of Disney's or the easter bunny or anything like that. Her cousins on the other hand ran screaming from the charactors, and still do ( age 4 1/2 and 3)