1. Facebook to Forum
The idea of having a CSS Facebook group is wonderful, but having this forum is a better place to discuss topics. When we have events, we can create the CSS FB event and create links from the event's page on FB to this forum. It will be our way of constantly reminding people about this forum and to have more people involved with discussions on this forum.
2. Face to Face
Remind people that CSS has a forum. Talk about the forum. Ask people to contribute to discussions on this forum.
3. Links
Put links to this site on your personal webpages. Alex added a link to this site on FB CSS group. If we don't already, we could add links on our wikispaces pages and our official CSS site.