The basic rules are, drop town ack, town down 75% (which changes the flag to white), and drop 10 troops of which ALL must make it inside the "map room".
Helpful tips:
1, dropping the VH at the field will help by keeping pesky vehicles out of the town and stop them from shooting your troops.
2, shoot the map room to kill anyone who may have bail and is waiting to shoot your troops as they run in.
3, Land troops with in 1 mile of the town. If troops are let out too far away they just stand around looking for a poker game. Troops can be dropped from the air and the best way is to let them out as you climb in a loop right over the map room. This way as they drop they fall onto of the map room and have less distance to run.
4, building down times can be extended by dropping the countries "city" and shortened by the enemy running supplies into the town to regenerate it.