I've spent most of my life picking routes/airlines by the planes you get. Currently, the best way to check planes IMHO is Orbitz.com. (I miss Sabre/easysabre--never had access to Apollo)
As airlines change their website every day, it's hard to suggest/know how they are at the moment--but typically, requesting a schedule just lists all the TIMES, but never the plane. You usually have to "select this flight" then "click for details" then click yet again for "more details"--THEN it'll usually say what type of plane. Takes forever. Some airlines will display the type of plane right in the "basic" results, but as I said--airlines constantly change their websites. Thus, I use Orbitz, as it will show all the airlines, with the exact type of plane.
Now, if you're looking for a specific plane (and not what planes are on a specific route), try to find the PDF of an airline's schedule---they almost all still have them, even if a printed timetable no longer exists. This is the best way to find out what routes a specific type is on.
Finally---if you want an A380, you can ignore most all of that, as there's very few in service and they only fly a few routes, and most of those don't go to the USA. Currently:
Qantas, Melbourne-Los Angeles, Sydney-Los Angeles.
Air France, Paris-New York.