Generate content for home page

Hi,

Currently I am using aggregator summary module.

Now I want to slightly bend this module to meet my needs. I dont have in depth knowledge of drupal api,
but I can do it based on suggestions.

1) Currently this module displays feeds under path /aggregator_summary, I wants to display it on home page, I want to know how can I generate content for home page? which functions/hooks to implement.
link to any example?

2) I want to modify it, so if he/she is an returning user, it will display only new feeds since his/her last visit.
I think i will need to create a cookie on client, how can I?

thnx