How do I limit it to one article per page and make these additions to Leave Comments?

Hi.

Just recently got my self a Hosted WP blog. And I really thought the Atahualpa theme is awesome.

Just trying to figure out how I can limit it to only show one article per page. And wanted to make some additions to Leave Comments. I wanted people to have the option of leave their name, website, Twitter Id and receive a notification for followup comments(this will have to be optional).

Cheers.. Are