Natural Domains and Limits

Hi.

I'm pretty new to this thread, but am hoping that you guys can help me out.

Would the natural domain of 1/( 1-x) function be all real numbers apart from 1? This whole concept of natural domain seems to be simple, and yet this question is a bit fuzzy. Also, Would I be right in saying that the natural domain of f= ln(lnx) be 1, infinity? If that is the case, what would be the natural domain of f o f? And how would one go about finding the axes intercepts of y=(f o f)(x)?

Hope it is not too much trouble

Thanks in advance