I have been running a Linksys 4-port router here at home for two years now. It allows a great firewalled connection to three separate machines, allowing each simultaneous DSL access to each plus file-sharing and a network printer. Hell, after this, I'd run one on just one machine!
Set yours up as per the book, then use the services at
http://www.grc.com (free) to prove network integrity. It works, and it's safe.
PS: If Hanno doesn't want the C15TA info, I sure do...
... but I'll let Hanno decide... only one of us needs it, as we share, and he's been more industrious in this than I of late...