I personally weight train 3 - 4 days per week, with at least a day off inbetween. I start off and concentrate with a particular muscle group on different days, but try to finish off with an overall workout towards the end. I train usually 1 hour to 1 hour 30 minutes.
I try to vary exercises, always trying something new. Sometimes I break the 'every other day' rule and train three days consequitively - specialising only on different muscle groups.
On rest days I often cross country run with my dog 2 - 5 miles. I know that weight-lifting purists would complain that this saps alot of my muscle-growing energy, but what the heck, cardio is more important to long term health, and more to the point - I enjoy it!
What are my results? I don't think that I'm ever going to be He-Man, I'm 44 years old, and don't have a very big mass. But I certainly see and feel results on my back, chest etc. I'm slowly increasing weights too - thats a result that I can see. How long did it take? Probably a month or two, then I started to feel pecs! I also really enjoy doing it.
Hi reps/lo reps - maybe I'll try that in the future, but these days I usually go for 6-8 reps of whatever weight that I can manage up to that rate. Once I can reasonably easily lift a weight up to 7 reps or so, I step up the weight. I'm no expert, but I do notice that the experts rarely agree with eachother anyway. Read the various opinions, then do it as you enjoy doing it!