I can't seem to find a detailed breakdown of how to use Flight as a PC beyond what to expect of different maneuverability levels, but whenever flying is mentioned I sometimes come accross mention of checks to fly or stay flying. I have also heard that Perfect maneuverability lets you fly any direction with no penalties, so does that need any sort of check to use? If so, what check is this and in which book(s) would I find more about it?
According to Special Abilities (Fly):
Perfect: The creature can perform almost any aerial maneuver it wishes. It moves through the air as well as a human moves over smooth ground.
Since normal human movement does not require any sort of skill check, neither does flight with perfect maneuverability.
Also, as per Movement (Moving In Three Dimensions), a creature with perfect maneuverability has no minimum move speed to stay airborne and can hover, turn, move backwards and move upwards without penalty.
Note that Pathfinder, unlike D&D 3.0/3.5, has its own Fly skill. Creatures with Perfect maneuverability gain a +8 bonus to this skill but must still roll for things like hover, turn and so on.