Here are the Intro Puzzles, in order, as of June 2018.
The entry for each puzzle links to the puzzle's help page, and YouTube videos from Madde and Loci.
The videos don't have any voice narration, but they do include Foldit sound effects.
Madde's videos date back a few years. You may see some differences in the current intro puzzles, such as additional help popups. Some of Madde's videos were made using a German client, which ends up being a mix of German and English.
Loci's videos were created using the June 2018 release of Foldit, and are all in English. They include the newer intro puzzles, such as the ones introduced in November, 2017.