MtDNA and where does it come from?

[monaherrin]

I am interested in having my mtDNA doen, but what does it show?  Since I am a daughter, does it show my mother's female ancestors and not any of my father's?  My cousin is a daughter of my father's sister.  Will hers who her mother's mother's line?  How do we find the line of the mother of our great-grandfather or is that possible? 

Thank you

Mona