Dr. Mercola and muscle gain

I have always been a very active person, mostly with team sports and martial arts, but I have been weight training for the last couple of years in an attempt to build some muscle.

I have an ‘ectomorphic’ (at least I think that is what it is called) body type and find gaining size to be difficult. I have been following Dr.Mercola’s eating plan for quite some time now, and I find that I feel much better and have more energy than I did before, but it also keeps me quite slim. Is there anybody out there who follows this type of diet and has had success with building muscle, and if so, what do you eat, especially before and after workouts?
Also, I find that glutamine helps me to keep muscle on. Can anybody tell me how much I should be taking, and when I should take it?
(I weigh 150lbs and workout 4-5 days/week, and I have a very physically active job)
Thanks.