Gentoo's excellent documentation has helped me a lot in configuring my SourceMage system. :)

Package management and most other aspects that are specific to SourceMage are well documented here: http://wiki.sourcemage.org/

This is how you manage init services in SourceMage:

telinit list
telinit enable|disable <service>
telinit run <service> status|start|stop|restart
telinit move <service> <runlevel>