Want to do something AJAX , what do I need to learn

I am going to display a list of 'things', which would show basically
the thing title.
That title will be a link, and upon clicking title, I'd like to show
the entire record in another DIV without page refresh.
Anything in particular I should learn, aside from AJAX in general and RJS ?
I'd like some general suggestion how that gets accomplished.

TIA
Stuart