There are really only four steps that you need to learn:

In Reel and jig time:

 -  the setting step or pas de basque

 - the travelling step or skip change of step

In Strathspey time:

 - the setting step

 - the travelling step

There is a useful description of the steps by Dianna Shipman of Houston Texas.  She has also produced a manual which contains descriptions of the main formations and many other useful tips and information.