\_ I've been looking at a lot of the ports in the services file as well as what
\_ nmap finds when I do some port scans and I'm not sure what some of the ports
\_ that are opened do or if they need to be opened for network activity at all.
\_ In other words if I disable them will my system stop functioning?

Depends on whether or not you are using the services.  There's the
BOFH test though: disable first then blame it on PFY if you need to
reenable it based on user complaint.

\_ 111    sunrpc
\_ 113    auth
\_ 513    login
\_ 514    shell
\_ 515    lpd
\_ 
\_ I pretty much get the meaning of what each one is from the name except
\_ sunrpc.  Do they need to have an open port for someone to function on a
\_ local host though?  Are there any serious ramifications if I disabled them?

IIRC:
sunrpc: is just for NFS and other '"SUN" Remote Procedure Calls'
auth: is useful for remote servers to see who's on a particular port on
     the box (for irc, ...)
login: shoot now, replace with ssh
shell: shoot now: replace with ssh
lpd: remote to local printing...no local printer-->disable

David