Dimensional Modeling design

I am very new to Dimensional Modeling.
IS there any rule that i need to follow while designing my model.
Which data to move into Facts and Dimensions?
There are lot of topics covered in internet on the same.
But wanted to know a rule or something that i need to follow while analzying data.
I am a newbie sorry if this question is really basic to answer.Apologies again,

Here are the basics:

#1. Forget most of what you learned about entity relationship modeling. Dimensional modeling is a different methodology.
#2. Facts represent business events or states. They contain dimension foreign keys, degenerate dimension values and measures.
#3. Dimensions provide context to facts. They contain attributes of the entity the dimension represents.

..and read Ralph's book on Dimensional Modelling: http://www.amazon.com/gp/product/1118530802?keywords=ralph%20kimball&qid=1444391632&ref_=sr_1_1&s=books&sr=1-1