When you play as Terran it could be a good idea to play aggressively, because Zerg players and Protoss players get a better economy then you much faster.
When you are playing aggressive you are forcing your opponent to defend himself and using recourses on defense.
A tip is also to expand when you are attacking.
Btw: most of my videos will come from Forze, like this one.
Link: http://www.youtube.com/user/ForceSC2strategy?feature=mhum#g/c/55B18C1A341FDE9D
(10) Supply Depot
(12) Barracks
(15) Refinery
(17) Orbital Command
(21) Factory
(22) Refinery
(29) Starport
(31) Armory
(58) Command Center
(12) Barracks
(15) Refinery
(17) Orbital Command
(21) Factory
(22) Refinery
(29) Starport
(31) Armory
(58) Command Center
Hope this will help and Good luck guys!!!!