An interesting dilema

I know you've all heard this story before, but here goes anyway.  I'm 26, 5'11" and 150lbs.  I've always been a skinny guy, an ectomorph I believe, and have wanted to add some mass but no matter what I've done I can't seem to do so. 
 
My goal is to put on another 15lbs or so in the next year.  I don't have a problem with getting to the gym, I can go 6 days a week from 7am to 9am and have been for the past couple months. 
I know I also need to change my diet and am willing to do what it takes to accomplish my goal. 
 
Can someone point me in the right direction?  I'd like to figure out a good basic training routine that will work my entire body and an estimate of calories I need to take in (how much and how often would be great).  For me the working out has always been the easy part, it's the diet I'm afraid of.  I don't have much time to eat or many healthy options for food at work and have never been a big eater.  In fact I've been know to work through many a lunch. 
 
I'd love any help with this.  I've scoured the internet for info and have found a plethora of information some contradictory.  Anyway, with all the information out there it's hard to filter out what you need for your own personal situation.
 
Thanks,
-James

As you might expect, everyone is different as far as need go.
 
But the method of gaining weight is fairly straight forward.
 
If you consume more calories than you burn you gain weight.
If the calories you eat are in the right proportions and from quality sources and your training and rest are appropriate...most of that weight is likely to be muscle.
 
That said...read this..do the steps and then post any questions it does not answer!  It addresses just about everything you brought up...and some things you did not.
 
Note..total lifting time 40 minutes to an hour max.  Not counting pre-warm up and stretching and your cool down and stretching.
 
For Gaining Mass
http://www.discussbodybuilding.com/For_Gaining_Mass/m_111173/tm.htm
 

My Journal Gain Muscle - http://www.discussbodybuilding.com/fb.ashx?m=111173 Lose Fat - http://www.discussbodybuilding.com/fb.ashx?m=111175