Going back over some books me'ah I also found the subject of ports/services covered quite well in the "Hack Attacks" Series:

For those who don't have these - I and a few others in the pit recommend them:

Hack Attacks Denied. Chirillo. ISBN: 0-471-41625-8.
Hack Attacks Revealed. Chirillo. IBSN: 0-471-41624-X.

Plus they make great pillows.

Now back to my dust. Good stuff except for the tiny Cartmans' that come out of my ears.