Hi Craig,
Hope none of this sounds patronizing if this is not what your after.
1. Flares:
Flares are incendiary devices which burn different colours (like fireworks but they just burn and burn and burn they dont bang they float around for ages) and are usually shot by a flare gun.
Aircraft shoot white, green or red flares. White means that the pilot is compelled to land. Green, at night, means may I land, and by day means may I land in a different direction from that indicated.Red means the pilot requires immediate assistance
Control towers only shoot red flares. To a vehicle or aircraft on the ground this means STOP. To Aircraft in the air this means Don't land. Give way to other aircraft and continue circling.
2. Quadrantal Rule
The quadrantal rule is in place to vertically separate aircraft flying lower than Flight Level 245 that might otherwise be on collision courses.
The MAGNETIC TRACK (ie. heading corrected for wind drift, and not corrected for magnetic deviation) that your aircraft is flying determines what quadrant you use to select a suitable Flight Level to fly at. The way I remember it is my right arm is odd and my left arm is even and that if I make a slash through the air from top left to bottom right thats the direction across which I add an extra 500ft.