FS / inode / vnode refresher

[Roy S. Rapoport]

I've been a sysadmin for about 12 years now, and have a pretty decent
understanding of most things sysadmin.  I've got enough of an understanding
of how the UNIX filesystem works to explain, say, how files are stored, in
general, what inodes are, and what the diff between symlinks and hard links
is.  

I need to bone up on the lower-level details for an interview next week.
Having already done this on the network side (TCP/IP Illustrated is your
friend), I'm looking for refresher material on filesystem organization,
hopefully at a similar level (in other words, I'm looking for something
deeper than "a directory contains a bunch of files" and something a little
more relevant and high-level than "here's the code to directly manipulate
inodes").  At the same time, I have to shamefully admit that I'm trying to
figure out what the difference between an inode and a vnode is (remember,
there are no stupid questions, only stupid people).  

Any pointers?

-roy