How To Write In Sharepoint Log File

In case you need to fast implement logging into HIVE use this:
Microsoft.Office.Server.Diagnostic.PortalLog.LogString(“Exception – {0} – {1} – {2}”,”User Friendly Message”,ex.Message,ex.StackTrace);
How To Write In Sharepoint Log File
But in case you are looking for a robust solution:
The Logging Application Block