Front Delt Advice & Others

I need advice on properly working my front deltoids.

I have been doing front lateral raises but in doing so I injured my lower back badly that i couldn’t move.
I usually train my front delts right after chest doing 5 sets of front raises.

second.
I don’t have a barbell squat rack so i use heavy dumbbells on both hand squatting. -can i build up my legs with that?
i’m having trouble with the footing with the dumbbells also. is there an alternative using dumbbells to build bigger legs?

third. I have been doing some jogging, and i really don’t know how to jog properly. I think i’m jogging too fast cuz i saw some joggers taking small strides and i take bigger strides than them. in addition to jogging… will it hinder my calf training cuz of the extra
work on calves during the jog?
how do i schedule days in between from jogging and calf training?

fourth, i want to have better posture. what can i do to help me attain that goal? is it constantly being aware of it and correcting it? and is there a workout out there to help me with this?

Front delts - do reverse-grip bench press, as a bonus, your tris will grow a lot. Be sure to bring the bar down to below your nipples - not high.

Legs with DBs - try Rear Foot Elevated Split Squats maybe?
http://www.T-Nation.com/readTopic.do?id=1543621

Posture - go to the authors section on the left and find “Eric Cressey”. Also, click on the “Search” button and enter “posture”.

The search button is your friend.

lunge variations with the dumbbells are very useful
http://www.T-Nation.com/readTopic.do?id=1450802