Home network basics help

[Michael M.]

As a network newbie, I'm pretty befuddled by the range of options I've
been finding via Google.  It's a tough topic really to drill down in,
because it's so broad and everybody's set-up is a little different, and
practically everybody's network seems to involve Windows.

I'm trying to find out what is the simplest way to move files back and
forth between two machines on a very basic home network.  The network
*is* the two machines, plus a DSL router and DSL modem -- no printers or
other devices to worry about.

First, I need to move files from the Ubuntu OS I'm running now on my
iMac to a new PC (should be here Tuesday) also running Ubuntu.

Second, once I've transferred everything off the iMac, I'm going to wipe
it and reinstall OS X, and will want to be able to move files back and
forth between the Ubuntu PC and the OS X iMac.

So what's the easy way to do Linux => Linux and Linux <=> Mac?

-- 
Michael M. -- Portland, OR -- USA
"No live organism can continue for long to exist sanely under conditions
of absolute reality; even larks and katydids are supposed, by some, to
dream." -S. Jackson