mate what are your stats?
Height,
Weight,
est Bf%
I am also a skinny bugger, I started lifting when 59kg, and 173cm, I am currently 69kg same height..
AS mentioned eat heaps, you will notice once you start traing hard you will be wayyy more hungry...Eat heaps more, eat before and immediatly after the workout if you feel hungry ever it is your body weight potentially going down..
There are heaps of posts by people as to specifically what type of foods and when to eat them, to help gain mass..You will need to train hard and lift heavy.
But also remember that this is a long term goal, there are no short or quick fixes, it will take time, dedication, determination, and a lot of effort, you may not fit in with what your mates are doing, drinking, smoking, eating shiit, late nights ( you need heaps of sleep) etc all these will inhibit your growth.
Now because it is a long term target, dont go too silly strait up. I would concentrate on maintaing really good form, while doing these exercises, iand not go too heavy strait up, slowly increase the weights as you feel you are able whilst maintaing good form, you dont want to do yourself an injury that will stop you, or deter you from training..