If you haven't already found it, it sounds like the Asexual Visibility and Education Network website will be helpful to you.

As a few answers:

~Yes, asexuality is the lack of sexual attraction to others. Under that umbrella is a wide range of experiences; some have a libido, others do not; some want relationships, others do not; some want children, naturally or otherwise, others do not; some have history of abuse, others do not...

~ Some asexuals do still find people aesthetically attractive- that is to say, they can see beauty and appealing features in other people but that is not connected to sexual impulses. Some asexuals say it is like appreciating a work of art. Aesthetic attraction is not solely an asexual thing- aside from the usual, remember that straight people can rate the looks of others of the same sex. It's just that most people either don't see that as attraction or since it coexists with their sexual orientation, they don't see it separately.

~ Most asexuals claim to have never experienced sexual attraction, so as far as they can say they were "born" that way. There have been incidences of people currently identifying as asexual who, at some point in their past, did experience sexual attraction (but in order for this to be a change of orientation, it shouldn't be short term or explainable by other things, like taking meds that lower libido for example). Some members of the asexual spectrum, known as "grey" or "grey-a's", experience sexual attraction very rarely or under certain circumstances, in which they are not technically asexual but are alienated from mainstream sexuality.

Hope that helped a bit.