This is going to be a quite broad question, and any suggestions, examples, links are very welcome!

I'm looking for a good way to log my users session, and actions on the site up to a certain point.

The site in question is a site for doing bookings. The users start with doing a search, doing a few steps of data gathering and selections and end up with a booking.

So what I need to implement is some kind of logging of the current session variables at each step the user takes. And perhaps some other valid information. Logging should preferably be done to the a database.

At the end i would like to associate all these session with a booking reference. The goal is to later if something goes wrong with the booking or we need to investigate a situation have all information we need.

I understand log4net is a popular choice for logging, and used it a bit myself for simple purposes, but can not find any good examples regarding my situation.

This should be a common situation, i'm curious how others do it.