I have 3 simple rules: Be safe. Be Responsible. Be respectful. This might be a bit abstract for 1st graders...but it covers about everything.
My management system includes a Happy Camper Board, Campsite Points, and Camp Compliments.
Happy Camper Board:
My kiddos earn camper cards each day if they follow the rules and procedures of our room. Each card represents a quality that will help them be a Happy Camper: boot=they can stay in the appropriate area (no wandering around or bothering other groups, stations, etc.); canteen=they can speak at the appropriate time and in the appropriate level; backpack=they can keep their things to themselves and not bother other people's things; fire=they are on fire for learning and can stay on task; hand=they can give teacher their attention quickly (give me "5"). At the end of the day, they color in all the cards they earned in their CAMP notebooks. If they get a few reminders and aren't earning a card, it gets moved to the "Wrong Way Trail" until the behavior improves (easy to earn back at the beginning of the year...VERY hard at the end.)
Campsite Group Points:
Each group is called a campsite. Each has a different color, i.e. the Blue Campsite. I keep track of group points on the board and the group with the most points at the end of the week gets a reward. We eat in our classroom...so my standard reward is that they get to eat with a friend of their choice on Monday.
As a class, we try to earn compliments --especially from others. I keep track of our compliments by filling in a mystery word on the board (written right above the group points section). I will write lines for each letter needed to make the word and fill in one letter per compliment. It is a fun way to keep them guessing words that will make sense and fit. My rewards are things like: PLAY/RECESS (extra resess or play time), CORN/POPCORN (popcorn), MOVIE (during lunch), etc.