@joe It is your preference to give a "Permissive License" for the library. (i.e. BSD, MIT).
We should definitely follow the Open Source Initiative (OSI) approved licensing
About Open Source Licenses
Open source licenses are licenses that comply with the Open Source Definition — in brief, they allow software to be freely used, modified, and shared. To be approved by the Open Source Initiative (also known as the OSI), a license must go through the Open Source Initiative's license review process.
There are generally two types of open source licenses:
Minimal requirements on modification, distribution or copy
Preserving the freedoms by requiring the software to pass on the rights of copy
Remember, when making this decision the copyright holder must take into consideration the rights of the user for subsequent use of a piece of software.
Example: Under the MIT license you can use the library to make a proprietary piece of software and charge for it without any restriction and decide to not release the source. With a copyleft license (i.e. GPL) gives the developer the ability to only release based on the restrictions allowed by the original license.
In projects like this one, there really is not a need for anything more than the permissive MIT license, because it allows for copy rights and the releasing of the liability on it's contributors. Although it does not require the sharing of modifications to the software that may be a benefit to the software.
The open source organization entity should also adopt a CLA and contributing guidelines. (I will create and link here.)