Just started!

Hey guys my name is Alex, and I recently just got interested gaining weight considering I'll be 24 on Monday and on a good day I weigh 150.. I'm 5'9 and like I said 145-150lb and I'm pretty "cut" I guess but I'm only that way cause I'm small.. I'm a Diesel mechanic and controls electrician and the engines I deal with are pretty big engines so lifting heavy equipment is pretty regular. I was just on here cause a buddy of mine told me this was a great way to count calories and I thought branching out to see if anyone had a similar story or know of any good weight gaining ideas mixed with a good work out strategy. Friend request welcome. Thanks guys