Hi Josh...and welcome to the world of smoking!!! I'm fairly new to smoking also, but can share what I've learned so far, for what it's worth. Everyone has different methods and tastes, so you will get a variety of advise, but it will all be good. Just practice and experiment. One thing I'll suggest that I find very helpful, and I think others will agree, is to keep a log book of all your smokes. List what you're smoking, what you used such as rubs, injections, etc....and methods and temps. Then after the smoke and you have tried the meat, write you comments on what you think worked about it, what didn't, and what you would change. Trust me, it is had to remember all the different variations you might try, and it's easy to forget what worked for you and what didn't. With a log, you can build upon each smoke you do.
Ok, for the butt, I've used water, and I've done them without. I found that with my butts, it didn't really add to the moisture content on mine. But I do inject mine which I think improves the moistness and adds flavor. That is a matter of preference. So do and some don't. You can experiment and see what you prefer.
If you want to pull the pork, then I would recommend going to a higher internal temp. I've had good luck with about 205 degrees. If you want to slice, then you can go lower. Others can add there experiences with this....
Adding chips will depend on your smoker. With the MES, (I have the MES 40), you have to add them every half hour to hour, I found. Yours may be different. But as far as the butt, I use an internal thermometer, and smoke until it reaches around 140 or 150, then stop adding. I found that adding after that temp, the butt didn't absorb much more smoke. Just my experience...but others might have different opinions.
There are some good commercial rubs out there, Plowboys, Smokin Guns,etc. You can do a search and read up on them. I like making my own. Just more fun and allows you to experiment. I like the Big Bob Gibson recipe for a base, and then I adjusted for my own tastes. You can use mustard, it helps the rub stick, and you don't really taste the mustard after the cook. I found that I didn't really need the mustard for my rub, but again, just my own preference.
Most important...HAVE FUN.....take your mistake in stride, and learn from them. Don't be afraid to experiment and find the methods and techniques that work for your tastes. If you need advise, everyone here is great to help, so don't hesitate to ask.