One of the nice things about pork butt is that you really don't need a recipe
You can inject with juice, broth, etc. if you want to and give it a heavy coat of a dry rub and cook until your thermometer probe goes in like into warm butter.
But... There are a couple of proven recipes that you can use as a starter.
The Chris Lilly pork shoulder recipe is in the second post in this thread...
Also, the Virtual Weber Bullet site has their Reknown Mr. Bron recipe which is also ver good.
No matter what you do, pork butt is a good choice for a first cook. It is relatively inexpensive and is very forgiving. If you temps get out of control for a little while don't panic. The pork won't care. Just adjust your vents to get things back where you want them.