The DVD is a great guide to the six or so major movements in weightlifting and I found it was much easier to visualise what I was meant to be doing.
I got serious in May '11 and by Jan '12 my personal bests were a massive improvement over where I had started, and I found that I was really enjoying tracking my progress and getting strong and fit.
I'd gone from benching 80 kgs to a 1 rep max of 120kg, and squatting 90kg a 1 rep max of 160kg.
I found the major contributor to my improvement was
- consistency (3 times a week, every week), and
- focussing on getting the biggest impact for your time in the gym.
Even if you just squat and deadlift, I believe you're doing much more for yourself than by focussing on what most people do - tricep pulldowns and bicep curls.