darock's advice to start with ailerons is good, but I'm not sure he explained what an aileron is. In a rudder-only plane, the rudder steers the plane, similar to a boat, although in an airplane the rudder also causes the plane to lean (bank) into the turn. Ailerons are flaps on the wings, on the back (trailing) edge, that do the same thing--they cause the plane to bank. That's how real planes turn. It's not appreciably harder to learn ailerons than to learn rudder-only, but most RC planes--and all advanced RC planes--have ailerons.