Searching the forums is not terribly difficult. Up at the top of this page, there are two tool bars. The first, marked by the yellow word, "Sections," will contain the words, "Fedora FAQ." That's the best place to start.
After taking in the resources available there, and then coming back here to the forum, the tool bar immediately below the first contains a link named, "search." That's the one you want to search the forums locally. From the little box that drops down, select, "Advanced Search." That will open a very powerful search criteria selection page. You need to be a bit specific and creative here, and persistance is your friend. In this case, "play .avi files" turned up several pages of good links.