Scripting is the engine that drives it all. The scripting basics can be found at http://wiki.secondlife.com/wiki/LSL_Tutorial
There are also many free scripting available online. OSGrid forum complies useful scriptings: http://forums.osgrid.org/viewtopic.php?f=5&t=2233
The chatbot scripting works pretty well: http://forums.osgrid.org/viewtopic.php?f=5&t=138 What I’ve designed inworld such as waitress, hotel manager or sales person are using this script language.