Topic: rails+apache2+mongrel_cluster

hey all,
I managed to configure a mongrel+apache2 but now I would like to do a mongrel_cluster. For now I have a sites-available/myapp but when it comes to mongrel_cluster I need to set up myapp.common, myapp.proxy_cluster.conf and
myapp.proxy_frontend.conf and I couldn't find a tutorial that explain where should those file go. is it in conf.d or sites-available/ or else?

thanx in advance.