Normally if you need to recover erased files, you should immediately stop doing anything that may overwrite that info. Then set up a 2ndary storage such as external HDD or another partition to use as the location to save the recovered files to.

If you've finished recovering the files, just drag & drop the songs into iTunes program or use the Add to Library command under the iTunes File menu. So then they're all properly entered into iTunes. From there you can reorganise them by arranging them by artist or year or alphabetical title, etc. Then you can create your own playlists from within iTunes. The Smart Playlist function is very good to use for this. It can automatically set up a playlist realtime by defining what type of play list it is. eg: all songs belonging to a certain artist. Or all songs dated during the 1990's or most often played or by file size or song length, or music style, etc. Remember to have a look at the link I gave you above. And have a close look at New Smart Playlist option within iTunes. Else you can create manual playlists.