[Dovecot] Orientation and configuration help

[J Moore]

This sounds to me like a "RTFM" question, but I've read the Wiki, 
and looked through the m.l. archives as far back as July... I still 
don't have a clear answer, so I'm posting here :/

I'm currently using mutt as my mail client. It runs on the same host 
that runs the sendmail MTA for my domain. So sendmail "delivers" my mail 
to /var/mail/<username>, and I read it from that location w/ mutt, 
transferring the "new" mail to a folder in my home directory if I want 
to save it (/home/<username>/Mail/<foldername>). 

This arrangement has been convenient, useful and reasonably secure (I 
think): I can check mail from anywhere via SSH, and I don't have to 
worry about downloading virus-laden spam/shit to my Windoze (corporate) 
laptop.

Now, I want to change; I want to use dovecot to provide IMAP access to 
my mail. I'd like to do this in such a way that I can still access mail 
using mutt when I want/need to do so.

I've installed dovecot, and reviewed /etc/dovecot.conf. I think I need 
to do the following to get underway:

1) create a directory for Maildir-formatted folders:
   mkdir /home/<username>/Maildir

2) start the dovecot daemon

Is that it? Will dovecot "take over" from mutt, and put mail in my home 
directory? Or do I need to configure sendmail to deliver to dovecot?

Also, there are other users/email accounts on the mail server that I 
would like to leave "as-is". Over time, I may want to migrate them to 
dovecot as well, but I'm reluctant to switch everything over 
until I've had a chance to evaluate it.

Should I run dovecot as a "rootless" installation to get it for a single 
user, or should I just set my single UID in dovecot.conf?

Thanks,
Jay