1) Evolution is an email client, like outlook, not a server
2) Setting up a mail server is not easy the first time around.. ever. you need to learn the terminolgy, the processes, and the practices of running a good, secure, email server as they are sought eagerly by spammers hoping you left it open for relaying.
i doubt anyone is going to guide you step by step by step, becuase there are wayyyy to many options, depending on how you want it setup and depending on your current domain situation (own you own? hosting yourself? bought server space somewhere?).
i would suggest you read some how to's and work through it and make your mistakes, you will be that much better of an admin once you finally get it to work the way you want, and will be able to fix it yourself should something go wrong.
here are some helpful sites:
<---a sendmail tutorial
<---postfix, a sendmail replacement, and its documentation (which is very good). i much prefer postfix to sendmail, as its 100 times easier to setup and admin.
keep in mind, spquirrelmail is just a webmail interface for an existing mail server. it will need an IMAP server running to be able to access the email. i use dovecot
as my IMAP/pop3.
sendmail or postfix provides the MTA (smtp).. there are many others out there to.. like qmail..
dovecot, cyrus, or imapd provides the IMAP/POP3 interface, once again, there are many more available than those.
optionally, squirrelmail or openwebmail provides a web interface, but for that you will also need to setup and configure apache.
hope that helps, a little at least.