MPD runs on 6600 by default, so that shouldn't be a problem. I run it on my homeserver under a separate audio user, who's also in the pulse group to use PulseAudio on the attached speakers.
Everything should be pretty self a explanatory. The "holoscript" part gets executed by my configuration management tool, but it basically means that the two LoadModule lines are appended to the stock /etc/pulse/default.pa
Also, if you have a firewall, open port 6600 to LAN if desired.
PulseAudio on the other hand throws a fit. For reasons unknown to me, PulseAudio basically doesn't support running as a system-wide instance, so things get pretty messy if you want sound to come from multiple users (IE. Your user, and your mpd user). If you only ever use one user on your system, I'd recommend just running mpd under that user - I believe that's what I did to get it working on my computer. Of course, if you're not using PulseAudio then this isn't an issue in the first place.
This is the approach I took, and I think it works very well.
The only problem with that approach is it means that mpd is tied to your X session. I quit or restart X every once in a while and it's nice to have my music keep going during that time. But obviously that's not a use-case everyone cares about since most people don't have a reason to leave X.