Since some time I collect libré/free-as-in-freedom UX resources. Here some I found, please add yours!
Idno User Research
A nice collection of possible questions, guidelines and pretext.
Source: https://github.com/idno/User-Research
License:CC0
Usability.gov Templates
Lots of templates like reports, release forms, screeners…
License: Public Domain
Source: http://www.usability.gov/how-to-and-tools/resources/templates.html
Questionnaires
System Usability Scale
The System Usability Scale (SUS) is a well evaluated, time proven and easy-to-use short questionnaire to determine the usability of a product and to compare it to other designs.
License: Public Domain
Source English: http://www.usability.gov/how-to-and-tools/methods/system-usability-scale.html
Source German: https://experience.sap.com/skillup/system-usability-scale-jetzt-auch-auf-deutsch/
General Resources with section(s) on User Research
Usability in Free Software
A guide to improving the usability of (open source) software –
including sections or recruiting and research. Superpower: Can add a
5th essential freedom to Open source software: »The freedom to use
the program effectively, efficiently and satisfactorily«
License: Creative Commons BY-SA
Source: http://jancborchardt.net/usability-in-free-software#Participants
User Need Research/Ethnography
Beginners Guide to finding User’s needs
Disclaimer: I wrote this, so I am not impartial here. I hope it
helps along nevertheless 
A Beginner’s Guide to Finding User
Needs is a book
(~100p equivalent) on how to interview and observe future users,
how to analyze data and how to report it.
License: Creative Commons By
Source: http://jdittrich.github.io/userNeedResearchBook/
Visual User Need Research
Disclaimer: …I wrote that too…
Visual User Need Research is a beginner friendly, visual approach to finding out about how and why users are doing what they do (booklet-length, ca 15p). Reading the chapters on recruiting and interviewing in A Beginner’s Guide to Finding User Needs complements it.
License: Creative Commons BY
Source: http://jdittrich.github.io/userNeedResearchBook/
How to do a research interview
Since conducting research interviews relies on the »right«
behavior, a video is a great way to learn how to do it. This video
shows what to avoid and how it can be done better. (It is NC, so technically not libré, but it is rather useful and I did find no better one…)
Duration: 18min
License: Creative Commons
BY-NC-SA
Source: https://www.youtube.com/watch?v=9t-_hYjAKww
Steve Portigal on Analyzing Interviews
License: CC BY SA 3 or any later version.
Source: https://air.mozilla.org/rethink-your-research-approach-synthesize-your-findings-faster/
The Challenges of Small Business Owners
A visual summary of an ethnographic research, showing
participants, their statements and observations. Nice example of
what an ethnographic research can deal with and which data matters.
Duration: 9min
License: Creative Commons BY 3.0
Source: https://vimeo.com/66064252
Nookie tour - Commonwealth July 2013
An interview/observation of a man walking us through a shell
construction which is going to be his house while describing how he
wants it to be like when its finished. This too is a nice example of
what an ethnographic research can deal with and which data matters.
Duration: 9min
License: Creative Commons BY 3.0
Source: https://vimeo.com/70890195