I like http://disneyworld.disney.go.com/restaurants/ since it shows the actual menu. Once you find the restaurant, the "details" link will take you to their page & there are links to pdf files of the lunch/dinner/desset menus on the right hand side. Be fair warned that, as with all Disney websites, the funtionality is a p.i.t.a.
We always use the Allears menus when planning what to eat. Make sure to figure in the cost of drinks, tax, and any restaurant "premiums" for the time of year you are traveling.
There are no DDP restaurant menus. You order off the regular menu. There are many sites where the menus are available, including right here on wdwinfo.com. Disney also posts many of the menus on the Disney World website.