I agree!
After being in the military for nearly 6 years now, this gets drilled into me.
A good Diet is the most important thing in any work out plan! You've got to ask your self, what you want out of exercising, and set goals.
If you just want to bulk up, then yeah, lift heavy weights and drink a protein shake after. But only drink loads of protein if your going to use it properly. If not, your going to be shitting it straight out!
If you want to loose fat. Do loads of cardio! Do not take pre or post workout!
Wait until you have been exercising Correctly and got a good Diet for a few months before you start thinking about bulking and shredding and using supplements.
At work, I am forced to go to the gym twice a day. Right now I am bulking so I am taking a pre-trainer BSN Hyper FX and Gold Standard Whey for straight after.