I'm going to move this to from the disABILITIES Community Board to the disABILITIES Board because I think you meant it to go there.
Most of the parks have Mainstream Access, which means that the 'regular' line is accessible and there is not a different handicapped entrance.
This is a link to the official WDW website page of information for
Guests with Service Animals.
(EDITED TO FIX LINK on 3/21)
That link does list the attractions in each park that Service Animals are not allowed on; for those, you will need another member of your party to watch your dog for you while you ride. CMs are not allowed to hold or watch your dog for you.
When you get to the parks, pick up a park map for disabilities. You will find them by the large display of park maps at the front of each park. If you don't see one, you can pick one up from Guest Relations at the park or from the
ECV/wheelchair rental area.
The Guidemap for Guests with Special Needs has access information for each attraction that tells which entrance to use. It does say that Guests with Service Dogs should follow the handicapped access listed on the map. This is a quote from the map:
Walt Disney World Resort strives to provide mainstream access whenever possible; that is, all Guests utilize the main entrance to the attraction. However, accessibility varies from attraction to attraction within Disney Parks. The Guide for Guests with Disabilities and Park Guidemaps use symbols to indicate boarding procedures for each attraction. In addition, Guests should contact a Disney Cast Member at each attraction before entering. Mainstream queues can be found at these attractions at Walt Disney World Theme Parks
Most attractions for all parks are listed as "Enter through standard queue" for attractions without Fastpass or "Obtain a FASTPASS OR use Standby Queue" on the Guide for Guest with Disabilities maps I picked up in October 2009. There is also a large red box on the maps which says "Guests with any mobility or queue related assistance needs are encouraged to use the Disney's FASTPASS option where ever possible." There is the same explanation about how to use Fastpass as on the regular park maps.
These are the attractions in each park with a different method of access listed on the map:
MK
WDW Railroad: Enter using ramp on the RIGHT on Main Street
WDW Railroad: Enter using wheelchair ramp on RIGHT at Frontierland
Big Thunder Mountain RailRoad: Obtain Fastpass or see Host for options. If FASTPASS is not available, enter thru access on RIGHT
Country Bear Jamboree: Enter thru door on LEFT
Hall of Presidents: Enter through door on RIGHT
Liberty Square Riverboat: Enter through exit on RIGHT or LEFT
it's a small world: Enter thru standard queue. Follow directional signs to designated load area
Peter Pan's Flight: Obtain FASTPASS or see host for options. If Fastpass is not available, see a host for options.
Snow White's Scary Adventures: Enter through Exit on RIGHT
Cinderella's Golden Carrousel: Enter through exit on RIGHT
Dumbo: Enter using ramp on RIGHT
Tea Party: Enter through exit on RIGHT
Barnstormer: Enter through exit on LEFT
Space Mountain: Obtain a FASTPASS or see a host for options. If FASTPASS not available, enter through queue on RIGHT
Epcot
Spaceship Earth: Enter through the exit on the RIGHT or LEFT
Gran Fiesta Tour Starring the 3 Caballeros: Enter through the Standard Queue. Follow directional signs to designated load area.
American Adventure: See a host or hostess for access to second floor
Impressions de France: Enter through LEFT side of entrance hallway
Studio
Great Movie Ride: Enter through the Standard queue. A host will provide directions in the pre-show area
Studio Backlot Tour: Enter through the standard queue and stay to the RIGHT
Fantasmic: Enter through the standard queue and stay to the RIGHT
Animal Kingdom
Wildlife Express Train: Proceed through standard queue. A host will direct boarding
The Boneyard: Enter through the designated access gate
Everything other than these attractions I have listed say to enter through the mainstream or standby queue.
The maps are very easy to read (although the type is small) and I recommend you get one for each park. The access information is listed right on the map with all the other information.
There is some more information /links about travel with Service Dogs in post #3 of the disABILITIES FAQs thread.