Here is a collection of assets used by Halopedia such as logos, old and new.
Used to celebrate the release of Halo: Combat Evolved Anniversary. (used 2011-2012)
The full list of Halopedia's rotating site header images can be found here.
Halo Nation assets
Halo Answers assets
These assets were the most recent at the time Halo Nation merged into Halopedia. They may have been changed since, as stewardship of Halo Answers has transferred to Halo Alpha.