"I currently have 12lb main line and i am wanting some Braid but im not sure how heavy i need it?Help me.."
Matty, one of the great advantages of braid is that, pound for pound (breaking strain) it is considerably thinner than mono - so, if you are currently using 12lb. mono, you should probably be able to use 30lb. braid without an increase in thickness - or alternatively, you could use 15lb. braid, which would give a slight increase in strength and a considerably reduced diameter.
Jonty