Help! (corier-imap + webmail)

[Grant <orblists@orbysrealm.com>]

Hey,

I've been trying to a while to get a Imap server running with webmail,

I have installed courier-imap using apt-get and i have downloaded and 
extract/configured ISMail (http://www.insidesystems.net/projects.php) 
and i also installed exim4 using apt-get again.

I have looked all over the internet and at the makers sites, but i cant 
find anything simple and basic.

What i want to do is make this server handle mail for two domains.

Problem is i cant find anything about just adding domains to 
courier-imap, also to make things worse i cant find anything simple to 
addusers to the server...

I know i need to setup the domains before i can add users but i still 
cant find anything simple.

Could someone give me some help on this... i really want to get up and 
running so i can turn my old mail server off...

Specs:

400mhz Celeron
128mb Ram
4gb Drive

Running: Debian testing

If anymore info is needed let me know :)

Thanks.
Grant.