I'm putting this under the Beginners thread becasue despite hitting the iron religiously I've been 150-160lbs with minimal increases in strenght and size for 8 years.
I've wasted time and effort listening to the advice of know-it-all/know-nothings, pissed away a ridiculous amount on wonder supplements and almost gave up on trying to put on mass.
Finally, after performing self cranial-rectal-ectomy, doing a whole lotta research (including this killer site and a beat-up copy of Stuart McRobert's Brawn) I went from 160 to 210 and was lifting weight I never approached before. This was done in under 4 months (I packed on a little chubb, but actually only put an inch on my waistline).
So, as I said, despite "working out"for 8 years, having only now seen the light, I consider this time as the beginning of my REAL training.