Convert old audio cassettes to something that can be streamed.

I have some old audio cassette tapes of my grandparents talking about their lives. I want to digitize them, organize them and put them online so that all of my relatives can listen/download them. The copying them part is easy. I have digitized them and have one audio file for each cassette. I am at a bit of a loss as to where to go from there. For example, what kind of Audition project would best suit my needs, and lots of other questions, most of which I don't even know I have yet.

Any advice?