In reference to the NO supp...

These products are essentially an over-glorified (and generally overpriced) arginine supp. With a little creatine thrown in.

Their advertising generally centers around "getting energy and a high level 'pump' in your workout." The energy comes from the fact that there's usually a little caffeine in there. The 'pump' you get... it's simply vasodialation directly related to the arginine.

Arginine is a precursor to NO and what NO does is, relaxes the blood vessels (vasodialation). Sure, your veins look huge. But that really doesn't do anything for you during your workout other than make you look a little fuller.

The main reason in the BB world that arginine is supplemented, it increases natural GH production. In other words, you want it during your recovery times, not when you're in the gym shredding up your muscle tissue. It's best to take it an arginine supp in the evening (as opposed to right before a workout as often directed on these NO supps). Your natural GH is released in pulses throughout the day and night. The largest levels tend to hit early on in the sleep cycle. So in trying to get the most out of your GH, it seems more logical to do that around your body's natural peak release.

In the grand scheme of things, I wouldn't worry too much about the NO supp just yet. Like others have said, get your diet and training in check first, and start off with the base supps (protein, vitamins, fish oils, maybe some creatine).