All you have to do with pedia.txt is simply include the file (unchanged, if you'd like) in the .zip package and it will allow people to view pedia entries.
.bak files are Backup files and are not needed. Nor are .sav files, which are your save games.
You should always include a readme.txt file.
If you haven't already, you should seek out Leon Marrick's guide to advanced scenario design. It's available in many places, including at Platehead's (
http://members.xoom.com/platehead/ ). It might also be available on the CSC.