In the last couple of weeks I've decided to start hitting the gym. I'm a fairly skinny guy; I'm 6'2, 150 pounds. I've never really worked out for any extended amount of time, but I feel that I want to start working out as a part of my lifestyle and routine.
I've done my research, and so I know that the best way to put on mass is to eat lots of high quality food (foods high in protein/carbs/fats, about 4-6 meals a day) and to hit the gym using mostly the free weights with higher weight and less repetition. I've since joined a gym, and plan on starting very soon.
My main concerns are specifically WHAT types of exercises I should do to start in the right direction. I suspect that I should contact a trainer at the gym to help me with exactly how to do the particular exercises properly (I do know I should always keep good control of the weights and not rush through the exercises). As I've mentioned, I've read often that the free weights are better to use to get a better body workout (because free weights force you to do all of the work with all the resistance).
About manipulating my diet... Is there any nutritional supplement you would recommend that would work as a meal replacement so that if I'm in a hurry I have somehting to fall back on? Or would a simple whey protein shake 60 minutes before working out suffice? Also, what types of foods do you recommend? I've got the following foods on my list that yield good protein/carbs: cottage cheese, roast beef, eggs, milk, peanuts, chicken, and tuna. I know there must be others...
I guess the point of this post is so that those who know fitness can tell get into a little more detail about what I (and other people reading this post) need to do.
I really only want to start off small, with maybe 5-10 pounds of muscle gain over a period of time, whatever it may be. My guess is that I should ask one of the trainers at the gym to show me exactly
what and
how to do the exercises that will build muscles in my chest, arms, legs, back, and arms. My goal isn't to get really big, only to get stronger and feel better about my physique.
Any tips and advice would be helpful.

Also, any questions about what I'm trying to convey in this overly long message are appreciated and welcomed.
Thanks!