Hi Harry, the concept of building muscle is quite interesting in that each person adapts slightly differently, so the reality is that you need a deal of time to go through the trial and error phase to work out what works best for you, but in saying this you must place an overload on the muscles before an adaptation can occur. So irrespective of whether you are doing a one set to momentary concentric muscle failure, or performing what has been used as a beginners program of 3 x 12 on a range of movements, you must gradually add either initially reps or sets and then load onto the training equipment, to improve. So you will need to invest in some heavier DB’s with time, or go to a commercial gym where you have a wide range of exercises to work with. It is okay to work to muscular failure although you will experience a high degree of muscle soreness, it will not damage your muscles. I like to use the basics to build size, Squats, Dead Lifts, Bench Press, Bentover Row and Shoulder Press will be the movements to use, and a set and rep scheme of 4 sets of 6 – 8 reps and see how that goes, cheers, ashley