Basicaly what you'll need to do is:
Stage 1:
install Apache
configure Apache
install Tomcat
configure Tomcat
install "mod_jk.dll "
connect Tomcat to Apache using the "mod_jk.dll" (Tomcat will provide a "mod_jk.conf" for you to copy/paste into Apache's "httpd.conf")
Stage 2:
Define a Virtual Host in Apache's "httpd.conf" (ApacheHome/conf)
Define a Host in Tomcat's "Server.xml" (TomcatHome/conf)
Stage 3:
Restart Apache and Tomcat
Stage 4:
create in the VirtualHostDocRoot directory the following directories : "/servlet", "/Web-Inf/classes" and "/Web-Inf/jsp"
copy the "web.xml" file from one of the tomcat examples dir's to the "/Web-Inf/" dir
copy your servlets into the "/Web-Inf/classes" dir
now, to execute the servlet open a browser and type:
theAddressYouDefinedInApachehttpd.conf/servlet/ServletName
like:
URL
For more information on the steps above surf the Apache and Tomcat documentation

Good Luck!
Peter.