A Dedicated Space
What is the Best Way to Share?
The obvious first choice for sharing materials with colleagues is probably through your institution's learning management system. This can be particularly useful if all you want to do is share with those at your institution. It does not, however, allow for free access to the materials.
Another possibility could be the use of shared network space, but this, again, would be limited to those at your institution alone. Either of these choices would work if you wanted to get a small-scale OER project moving, to "test the waters," so to speak.
Though many of us have access to some institutional resource or another, it is still important to consider forging some dedicated space for the sharing of open content. This makes it possible for the world to enjoy our work (thus, literally, making it "open") and helps to ensure that nobody gets confused about what kind of material they're dealing with.
One such possibility would be the creation of a webpage for hosting shared materials. Many institutions (most, actually) already have some such public content available, but it is, ironically, not often appropriately licensed for sharing. To facilitate the sharing of open resources, consider setting up a basic blog. You can post materials to the blog and include descriptive tags so that visitors to the site can simply enter a search and see what you've got available. Another possible structure would be to post the content on static pages that are organized around specific courses, each branching off from the website's home page.
Finally, there is the possibility of offering your material up to an online collection.