This is a really good question and I'm glad you asked it. I used to smoke a ton at work. In fact, it wasn't uncommon for me to smoke an entire pack in 8 hours. When I was on midnight shift, it was often times just myself in a huge building built in 1903. I could sit atop and watch DC as it slept or sometimes not. Either way, it was wonderfully quiet, beautiful sights and it was just myself and my thoughts. I didn't have to worry about other people coming and going thus affecting the need to feed my addiction.
Day shift I also smoked while working, just not as often because there were many more things to deal with; people being at the top of the list. Yeah, people = stress. Still I would catch a smoke pretty much whenever I wanted but certainly not like the carefree midnight shift.
When I quit smoking, I kept myself busy and if my work was done, I found more. I kept printouts of the Quit Smoking Recovery Timetable on me and had several key topics bookmarked on my phone to read if I was getting antsy and wanted a cigarette. I kept Allen Carr's book with me and also had certain pages of it bookmarked.
Lastly, the crankiness you're experience will go away. Once you get the nicotine out of your system (3 days or so) the rest of psychological and this is where you really need to learn and understand about this addiction. You can start with watching the videos concerning issues when you first quit. Come here as often as you can. If you think you're going to smoke, post an S.O.S. on this specific board. Myself and many other members get alerts to our phones and email whenever somebody posts a new topic on the S.O.S. board. Somebody will there quickly to help get your through.
How To Quit Smoking
Video lays out simple tips for people wanting to quit smoking.
https://www.youtube.com/watch?v=l27zWo7hbcY
Related resources: Quit smoking tip sheet http://whyquit.com/joel/Joel_03_01_ti...