Newbie Tasks Project
Promote and use the newcomer tag
Clean Spam in Debian Women mailing list archives or in other Debian mailing list archives.
Update existing translations of website pages - many pages just need some lines added or deleted. Please check the stats for your language and contact the Debian localization team for your language.
These are videos that may be interesting to watch in order to quickly learn how certain teams work, how can you join them and in which tasks you can help.
"Get involved! It's not that hard! Five paths to become a Debian contributor" Mini-Debconf-Paris 2012 (8min, English)
Why to contribute to Debian "Por qué contribuir a Debian" Debconf 2009 (Spanish)
Quality Assurance (QA), entry point to the Debian project "QA una puerta de entrada al proyecto Debian" talk at Debconf12 (Spanish)
"Introduction to Debian translation workflow and processes" Debconf12 (English)