Hello businessgeeks,
I in process of building such a cluster. I will eventually write such a procedure after everything is working + tested. In fact, there are many ways to achieve such a task. What task will your cluster be built for? How critical is your application? What resources do you have (hardware, time)?
Heartbeat is only a part of the solution. You will also need to replicate your data from one machine to another. There are multiple ways to do this. You can setup basic replication between your MySQL nodes. You can also build a fancy MySQL Cluster (separates data from management and from API nodes). This approach is much more scalable but a little more costly on the resources side. I recommend you check out those links:
http://dev.mysql.com/doc/refman/5.0/en/replication.html
http://dev.mysql.com/doc/refman/5.0/...l-cluster.html
Once all your nodes have the same data, you can check out heartbeat, carp and even MySQL on how to switch from one machine to the other in case of failure or on how to distribute the load as evenly as possible.
Let me know if you have any questions.