Any info to help a guy who is 6'3 and weighing at a whopping 69Kgs would be great
I'm 5'7" and the same weight :O
You need to eat, son!
If you want to build weight in a hurry, I have heard that full cream milk is great due to the reasonable levels of fat and protein, but obviously your intake needs to be proportional to your level of physical activity or you'll just get fat
ALSO, that's just from what I've heard, I don't drink milk myself these days... I can't remember why, I stopped for some reason. It could be due to me quitting every liquid except water.
I've found the the key is to underestimate your energy needs for the day, and that way you'll find that if you're not getting enough you quite simply will get very hungry. And from there, you can adjust your intake accordingly. If you start off eating too much, you may end up putting on too much fat too soon and will find it harder to break the habit.
Airstrike - I know I'm not Hamatime, but I'll offer a different perspective to the typical bodybuilding ideals:
Day 1: Using tabata intervals (20 seconds work, 10 seconds rest), do pushups for 6 - 8 'sets', and then do the same with unweighted squats
Day 2: Deadlifts and Ring Dips (on bars if you can't do ring dips yet)
Day 3: Front Squats and Pullups or Chinups
Depending on your goals, you'd vary the sets and weight of each exercise. Wikipedia has a good list of weight percentages of 1 rep max, the amount of reps, rep speed, number of sets, and rest times depending on what you want to achieve.
So for example, at the moment I've got a strength bias, so I'm doing 7 sets of 1 rep, 6 sets of 2, 5 sets of 3, and 5 sets of 5, increasing or decreasing the load depending on how I feel. Obviously, correct form is the most important thing. When I feel like having more of an endurance and sarcoplasmic hypertrophy effect, I do 6x6, 5x8, 4x10 and 3x12. I rotate between the different sets + reps each time I do the exercise, which is usually once a week each.
This is a pretty rough outline of the way I do my own workouts, it may or may not suit you but it works for me
Current I deadlift 155kg, front squat 105kg, push press 80kg (like a shoulder press but using a little momentum from the legs)... I can also run a 10.5 on the beep test on a good day, and I'm building up my muscle-up count... 13 successful muscle-ups out of 21 attempts in 10 minutes... Not great, but I'm getting there