Need help with the sideline instructions

i've been playing FM2010 since it was released 31st of Oct.

and till this day i'm not exactly sure when to use the sideline instructions during the game (attack-control-overload....etc)

can anyone tell me when to use any of those exactly ?

and how it will affect the match ?

if anyone could explain every one of those i'd really appreciate it.

and i already read what they means in the game itself, but i did not get it.