Five Rules for Traffic Cycling

1. Drive on the right side of the road, never on the left and never on the sidewalk.
2. When you reach a more important or larger road than the one you are on, yield to crossing traffic. Here, yielding means looking to each side and waiting until no traffic is coming.
3. When you intend to change lanes or to move laterally on the roadway, yield to traffic in the new lane or line of travel. Here, yielding means looking forward and backward until you see that no traffic is coming.
4. When approaching an intersection, position yourself with respect to your destination direction -- on the right near the curb if you want to turn right, on the left near the centerline if you want to turn left, and between those positions if you want to go straight.
5. Between intersections position yourself according to your speed relative to other traffic; slower traffic is nearer the curb and faster traffic is near the centerline.

... a sixth rule of the road. Be predictable. This means to ride a good straight line, signal turns and lane changes and generally look like you know what you are doing. If you act like the driver of a vehicle, then other drivers will usually understand what you are doing.

full text http://www.bicyclinglife.com/practicalcycling/commuteguide.htm