I have found that many articles found on the net are good and detailed but they are not really friendly to novice programmers. In my article the topic is presented as a Q&A session. Most of the questions are the ones that most novices would like to ask.
Slony-I is a "master to multiple slaves" replication system supporting cascading (e.g. - a node can feed another node which feeds another node...) and failover.
If you have a busy PostgreSQL or MySQL database application, you might want to analyze the queries to see if they can be improved. Here's a little utility to help with that.