/var/log versus system crash examination

[<tomas.itsx@centrum.cz>]

 Hello debian users,

 i have quite a newbee and a general question, so i will appreciate any
 hints and links to a good materials and so.My problem is:

 i run a kind of  a long-time computation software (gromacs) on my 
 debian etch box, but unfortunately i receive crashes of the system
 (debian gets frozen).So in order to find out the source ot the problems,
 i would like to examinate the /var/log directory.

 What i would like to know is the relevance of the particular logs, which are 
 situated in the directory.

 Namely: kern.log,messages.log,syslog,user.log,

 My goal is to be able to diagnose my system crashes.
 So i would like to ask for good materials to learn the logging 
 machinery in debian about.

 best regards
 itsx