Getting started with protocols, master/slave bus

Using Arduino Project Guidance
1

Hi,

I was looking at a demo of someone reading the information from his car: http://vimeo.com/84498522

Now, I was wondering where/how to get started with building small networks:

a) What concepts are behind the use of a master-slave bus or e.g. using master-slave devices in the LIN protocol?

b) What are simple projects to get started with building a network of devices?

Thanks!