List of categories and posts on front page

Hi
I’m looking to modify the home page of a WP site to include a list of categories and posts. I have done lots of searching and playing around with this but havn’t hit on a solution yet due to my non coding skills!

I would like the new element to look like this
HEADER
NAV

CAT 1___________________________CAT 2
* post a (5 comments)* post a (5 comments)
* post b (2 comments) * post b (2 comments)
CAT 3___________________________CAT 4
* post a (5 comments) * post a (5 comments)
* post b (2 comments) * post b (2 comments)

START STANDARD CONTENT

I have been playing around with the list all posts plugin which allows me to do this on a page, but I can’t insert the functions in a template file. So I think I need someone to offer me up some nifty PHP code.

Any ideas?
Thanks in advance.