It depends on what you're comfortable with. Typically, I will take some Nyquil or Alka-Seltzer Cold (Nightime) before I go to bed for the first two nights. For me, the first two nights are usually the hardest when trying to get to sleep. After that, it gets a little easier and by weeks end, I usually end up on a normal sleep schedule.

If I can coordinate it all right, then I just go out drinking with some friends or at a bar and get sloshed. Usually one night of some hard drinking will do me fine and I don't need anything after that to get back to sleeping normally.

If neither of those are an option, than just having something to do is good. I've played video games all night to make it through the first night and then ended up back on a normal sleep schedule. A long interstate drive also works, if thats an option. Excersise is definately a healthy and viable option.

The one thing I'd advise against is any type of sleeping pill. They tend to be too weak and sometimes you can get dependent on them to fall asleep, not a good thing.

As far as your tempermant, I don't know. I'm crabby by nature so I don't notice a change when I stop smoking. The only advice I could give is to think before you speak or act.