i've got a very high metabolism too. the only way i've found to gain weight and muscle is to eat a hell of a lot and work out regularly. us skinny people gotta work harder than the rest!
with each meal, i'll eat until i'm full, rest then eat another half serve of what i just had and worked out for an hour and a half 4 times a week (workout, rest, workout etc) and did cardio first before weight training (aimed for at least 75% max weights and sets). exercises that combine two or more moves like diver bomber push ups, dumbell squat thrust with shoulder presses and uneven moves like lopsided dumbbell push ups. focus on strength training 'cos the rest just follows.
meals were comprised of equal serves of carbs, fat and protein (kangaroo meat pasta is great and stirfry with rice too). i gained around 22lbs in 10 weeks doing this and before i did this routine it took 4 years to gain 8 lbs (i was working out but not eating enough to fuel my exercise regimen). i hope this helps!