There are a few rules to rotaries.
#1. Traffic already inside the rotary has right of way.
#2. The outside lane is for taking the first or second exits only. You may not go all the way around the rotary in the outside lane.
#3. The inside lane may be used for going beyond the first two exits.
#4. Once inside the rotary, do not stop. Rotaries are designed so that traffic inside the rotary does not have to stop, if you stop, drivers behind you will not be expecting it, causing the risk of a rear-end collision. If you cannot get to your exit, simply drive around the rotary again.
Some dumbass in an SUV talking on a cell nearly sideswiped me when he/she couldn't stay in his/her own lane in the rotary!
<nooblet> sweet!! start it!!
<cool guy> HELL NO it will cost me too much in gas :@
Note: Proper rotaries ah big, typically where several roads (two main roads) come together. They are not to be confused with roundabouts, which are cute, dainty little things used to "calm" traffic in subdivisions.
I just learned this was a New England thing, who knew.
Usually there are a lot of stores all around it, and like a little "green" in the center with some memorial.