Hi H.. I traveled with my son when he was 3 months old and I was scared about the ear thing too. I talked to my docter and to the pharmacist and they recommended a small dose of Sudafed. They only make it for children and it's available behind the counter but if you give your child a little less then a half of a tsp just before you go onto the plane then this will help keep his/her ears from plugging on the way up or on the way down.
We flew from Seattle to San Diego and back while making one layover with each flight. It was a little hecktick at times becuase my son started getting bored at times but he loved looking out the window when the plane took off or when he could see the ground. So I definantly recommend a window seat if you can get one. Also bring lots of entertainment but not to too much. You want to make sure that he/she is kept busy so theres less fussing but too many toys can be hard to keep track of on a plane.
Also I noticed that when he was drinking a bottle it seems to help calm him down when the airplane was taking off or getting ready to land. He was too young for juice at the time but since your child is 11 months, juice might be a good idea... it's kinda like chewing gum for adults.
Well, I hope this helps you. Have a great trip! DisneyLand is ALOT of fun, but be sure to bring a stroller.
When your at DisneyLand... be sure to use Fast Pass instead of waiting in those long lines. You can walk to the front of the line and there will be a fast pass machine... print out a ticket and then work your way to the next ride that you want to go to and do the same thing.
Those tickets will print a time frame for you to come back in about 2 hours. Then when you come back you can get in the fasst pass lane and it is sooooooooooo much faster. It's been probably 3 years or so since I've been there but I'm sure this system is still in place. Use it, you'll love it.