Vista Network

I'm having huge trouble connecting my XP Pro laptop to my Vista Ultimate PC.

My internet connection on the Vista PC works fine, but connecting the two
machines together on a separate network is not working.

On XP there was a simple wizard that made this work easily, but I can't find
this on Vista. Some online documentation points me to similar things, but
these are not available (or not where they are claimed to be) in Vista
itself. This may be a difference between Home and Ultimate, or a change
since the Beta releases.

Last night I did manage - after a lot of fiddling - to get the LAN working,
but I could not see the shared internet connection on my PC from my laptop.
When I turned it all on this mornig, the LAN had stopped working again.

Any ideas, or does anyone know of a website that gives a clear explanation
of how Vista networking works. The Vista help seems to imply the 'it just
works' - which is kind of irritating when it just doesn't.

Thanks in advance,

JK