log4net is a proven and simple means of enabling logging in your .NET application.  There are lots of resources available to walk you through the standard setup process, but I will give some steps for more advanced scenarios with multiple projects in a .NET solution.

One Config File, Multiple Projects

 In most circumstances, it is nice to be able to share a global log4net configuration file for all of the projects in your solution.  This way, you can make changes in one place and the next time you build, it will take effect for all logging in your project.

To ...