First priorities:
1. Make sure the translate extension is in place and working well. If not done yet, or not enough, we need a few test users and pages to play around with. We already done some of it. Is it usable yet in other opinions?
1.a. Add an easy link to Special:PageTranslation for members with pagetranslation permission.
1.b. There are a few goodies that don't seem in place yet, like knowing that "en" is the main page (not a translated version) or recognizing user's language from sm.org forum.
1.c. There should be links to available languages for translated/translatable pages directly on the page, a combo perhaps.
2. Document how the extension works, for administrators and for translators. Useful doc:
http://translatewiki.net/wiki/Translating:Page_translation_feature
This documentation should be in the wiki itself, though a topic/blog on sm.org community forum should point to it.
3. Import into the wiki the existing translations for a number of pages.