I will add those videos to this section ASAP - https://www.zeescripts.com/tutorials/
Meanwhile in Digital Download Script Follow these Steps:
1. Keep your zip file ready – label it something to recognize your ebook Title. Upload this from admin > Catalog > Downloads > Insert Button.
2. Create Categories and Sub categories in your store from admin
3. Go to CATALOG > PRODUCTS in admin, Then CLick Insert Button on top right.
The rest you can follow the tabs and if you have enable downloads, select the file you have already uploaded in step 1.