Undecided questions
What is the different between "SER" Y "ESTAR"

This link explains it better than I ever could:

http://www.studyspanish.com/lessons/serest1.htm

Check it out.

The link 'Sakaverde' suggested you is really clear.

I was trying to find the easiest way* to explain it though.

Ser is used for:

1. origin
2. physical traits
3. fairly permanent things

Estar is used for:

1. location
2. emotions
3. state of being
4. fairly changeable things

*(Google Search)



=)

This will be one of the first sections in any good Spanish grammar book.