First, don't do the things that destroy community.
Next, read Art Of Community and WikiPatterns for wisdom, tips, and tricks from other communities.
Conduct your wiki activities according to the Leadership Code of Conduct. Help others, be nice.
Also communicate, a lot.
After that:
Zoltán Horváth edited Revision 20. Comment: adding hu-HU version link, small HTML cleanup
Dave A Gordon edited Revision 19. Comment: Corrected grammar - Find to Found in "After that section - Bullet 2"
Luciano Lima [MVP] Brazil edited Revision 18. Comment: Update link Wiki: Como Construir uma Comunidade (pt-BR)
Horizon_Net edited Revision 16. Comment: added language tags
yottun8 edited Revision 12. Comment: Added "Other Languages" and ja-JP link.
Ed Price MSFT edited Revision 9. Comment: Inserted horizontal lines.
Pronichkin edited Revision 7. Comment: Minor (removed double space char)
Pronichkin edited Revision 6. Comment: Minor edit (text formatting, etc.)
Ed Price MSFT edited Revision 5. Comment: Added "Things That Destroy Community" link.
Ed Price MSFT edited Revision 3. Comment: Refined title, minor edits, and added "See Also" and "External Links" sections.
Thanks, so helpful.