Beginner's Corner may not be the place to get your answers.
For starters you will need some sort of load balancer in front of your HTTP cluster, be it HW (Alteon, BIG-IP, etc) or SW based (Apache JK/JK2). I would recommend the following for more info:
1. Buy the for-pay clustering docs. It's only $10.
2. Check the FAQ forum. There are some posts there describing HTTP clustering environments and architecture.
3. Check the Clustering Forum.
4. Buy the for-pay clustering docs. It's only $10. :-)