I have a large collection of ebooks (mostly .PDFs) and training videos (variety of formats) that I often have a hard time sorting through. Since many of the ebooks and videos cover the same topics (i.e. photoshop, webdesign, homebrewing, etc), I would like to find an application that allows me to catalogue and sort through both of these types of files. I am currently using folders in Finder to keep them somewhat sorted, but I find that this is not sufficient for me. Ideally I would like an application that allows me to view these files within the application or at least click on them and the respective viewer will open up (i.e. quicktime, preview, etc.) Any recommendations? Thanks in advance.