Log
links:
Comparison of .NET Logging Frameworks and Libraries
Solving database logging bottlenecks with NLog
Why I Switched from log4net to NLog
Common Infrastructure Library, Chapter 1. Common Logging
ELMAH: Error Logging Modules and Handlers for ASP.NET (and MVC too!)
Error and Event Logging in VB.NET
HOW TO USE LOGGING IN C# .NET PROJECTS?
Is there a logging facade for the .NET world?
SLF, the Simple Logging Façade, Hands-on Tutorial, Part 1