Getting to (and around) Anaheim and the OC is easy! If you're flying (in an airplane), you have four options. Four Airports service the Orange County area:

John Wayne Orange County Airport (SNA) 20 minutes, 13 miles/21 km to Anaheim
Los Angeles International Airport (LAX) 50 minutes, 35 miles/56 km to Anaheim
Ontario International Airport (ONT) 45 minutes,  36 miles/58 km to Anaheim
Long Beach Airport (LGB) 30 minutes, 18 miles/29 km to Anaheim

Once on the ground, I would recommend renting a car so you can explore the different parts of the county. All the major car rental agencies have desks here.