You can use the Amazon Web Services (AWS) Management Console to create a classic load balancer and add Elastic Compute Cloud (EC2) instances to it. Follow the instructions in the AWS help to create a classic load balancer and add instances to it.
It's recommended that you add instances from a variety of availability zones. This way you still have a running instance if a zone becomes weakened or disabled for any reason. Amazon recommends maintaining the same number of instances in each availability zone because the load balancer distributes traffic equally across availability zones.