freenode-channel-setup

Join the channel you want to register. Make sure you're an op (either the first to join, or someone who is an op there sets you to +o).

/join #newchannel
/msg chanserv register #newchannel
/msg chanserv set #newchannel mlock +cnt-s
/msg chanserv set #newchannel guard on
/msg chanserv set #newchannel secure on
/msg chanserv set #newchannel topiclock on
/msg chanserv set #newchannel keeptopic on
/msg chanserv set #newchannel url http://example.org/
/msg chanserv flags #newchannel ownernick FOUNDER

For more info, /msg chanserv help