Is there a buying guide for the mk 2 octavia, I'm looking at some over average miles VRS petrols.

To be fair treat as you would any car. There are a few common issues of the top of my head leaks, saw toothing. Best thing to do is spend an hour reading through the common posts.

With all cars if in doubt take someone that does know about the oily bits.

Plenty stuff around if you have a search. Here is a start -

http://www.briskoda.net/forums/topic/253356-looking-to-buy-mk2-vrs-whats-it-like/