Generally a log file is one that is created, usually automatically, by a process such as an automated test or a program. Depending on the settings in that process, different items are written to the log to track the process activity, errors etc.
Your analysis would be to understand what the creation of the log file purpose is, what the items are that were supposed to have been written to that file and what each item means.
Decisions on that process will be made depending upon what the log file has related to you about the process's activity and quality.
Kind of vague, as Charles said, before we can give you more details, we need to know what kind of log and analysis you've got to get through.
You see, a log could be a whole lot of things to a lot of people.
A traffic accident log could be tire tracks on the road.
The analysis could be understanding what direction they are going, or what kind of tire created them.
An internet activity log could be your cookies on your PC.
The analysis could be what sites you visited or how long were you on the net on a certain day.
I've mostly dealt with logfile analysis for web sites. See links to related information at http://www.wilsonweb.com (search for articles on "logfiles" or "web site statistics" or ...)Or just do a general web search for these terms.
I like NetTracker and that web site has some information on logfile analysis. See http://www.sane.com
Do many of you analyze web site logfiles? If so, I can provide more information on something that just started happening if you use Internic/Whois - it affects our ability to resolve IP addresses. If people aren't interested, I won't take up the space here.