Something Wiki This Way Comes

Many formal archives began as a single fan's collection, which was passed to a library. That library took on the responsibility of collecting, curating and caring for the archive. With modern technology, curating an online collection can be crowd-sourced, but still often begins as a single fan's labor of love. Wikis, databases, Pinterest are all ways of collecting and sharing a body of knowledge. Why do we love gathering all that information, and what mediums are best for curating and sharing it? If you're part of a fandom, what are the best practices for starting your own virtual collection?