There are three hotels on Disneyland property, but it is not necessary to stay at a Disney hotel to go to the parks. These hotels include The Grand Californian (where the wedding will be held), The Disneyland Hotel, and Pixar Place Hotel.
We typically stay at hotels that are not on Disneyland property. This link provides a list of hotels that Disney recommends. Our favorites include The Candy Cane Inn, Grand Legacy at the Park, Hilton Anaheim, and The Tropicana.