I'm going here this October.

The Dia das bruxas stuff lasts all October; it will most definitely be there...

Anyway, it really all depends. We'll start with food. If you want to do sit down, then you should start making reservations three months out. They can be hard to get into otherwise

Magic Kingdom: Not a lot of good sit down places, and the new Be Our Guest Restaurant will NOT be open yet, so I recommend this: Liberty árvore is a really good sit down lunch place; you can do that and then one of the quick service places for dinner. You can also eat at one of the surrounding resorts for dinner. The best counter service place is Cosmic Ray's Starlight Cafe, and it also has the most options, but all of them are good.

Epcot: THIS is the place for sit down restaurants.

-Les Chefs de France: French cuisine, very good
-Tepan Edo: Japanese steakhouse, never have had a bad meal here
-Les Cellier: A bit pricey, but a good Canadian restaurant. The bife is really good

Again, any sit down place is good, but I would avoid Electric Umbrella just because it happens to be the worst in the park.

Hollywood Studios: comida generally stinks here for some reason; quick service locations are about even on quality. For sit down: Prime Time Cafe: Classic American Cuisine in a fun environment

Animal Kingdom: Get a park hopper and head over to Epcot for the evening for dinner. If you like Buffets, you can also head over to Boma's at Animal Kingdom Lodge

Counter Service: Pizzafari and Flame árvore Barbeque are the best. I like Pizzafari.

As far as rides, there are too many to name. You must do:
-Space Mountain in Magic Kingdom
-Soarin' (get a Fastpass) in Epcot
-Star Tours in Hollywood Studios
-Tower of Terror in Hollywood Studios
-Rock 'n Roller Coaster in Hollywood Studios
-Expedition Everest in Animal Kingdom (get a Fastpass as soon as you get there)
-Kilimanjaro Safaris in Animal Kingdom (bring a camera)

Save the shopping for World Showcase in Epcot. Also check out Mousegear, also in Epcot.

If you have any questions, feel free to ask me