For log4net implementation - sample configuration:

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <!-- Register a section handler for the log4net section -->
	<configSections>
		<section name="log4net" type="System.Configuration.IgnoreSectionHandler" />
	</configSections>
	<appSettings>
	</appSettings>
	
	<!-- This section contains the log4net configuration settings -->
	<log4net>
		<!-- Define some output appenders -->
		<appender name="RollingLogFileAppender" type="log4net.Appender.RollingFileAppender">
			<file value="rolling-log.xml" />
			<appendToFile value="true" />
			<maxSizeRollBackups value="10" />
			<maximumFileSize value="10KB" /> <!-- can use KB or MB -->
			<rollingStyle value="Size" />
			<staticLogFileName value="true" /> <!-- Means main log file will always be the one written to -->
			<layout type="log4net.Layout.PatternLayout">
				<header value="[Header]&#13;&#10;" />
				<footer value="[Footer]&#13;&#10;" />
				<conversionPattern value="%date{MM/dd hh:mm:ss.fff tt} [%thread] %-5level %logger%message%newline" />			
			</layout>
		</appender>
				
		<!-- Setup the root category, add the appenders and set the default level -->
		<root>
		    <!-- Possible are ALL, DEBUG, INFO, WARN, ERROR, FATAL, OFF -->
			<level value="ALL" />			
			<appender-ref ref="RollingLogFileAppender" />
		</root>
		
		<!-- Specify the level for some specific categories -->
		<logger name="GoldPocket.Gateway.InternalTools.Helper"><!-- Should be like Namespace.Class -->
			<!-- <appender-ref ref="B" /> -->
			<level value="ALL" />			
		</logger>
	</log4net>
</configuration>