Q: how/where do I host the files so that people who buy can be redirected after paying to get them?
A: you could do what I did. I put them into a box.com folder & shared it – dropbox would do the same thing. Probably easiest for MP3 files.
You could also upload them to soundcloud like Phyllis Wilson did and embed the code onto your page.
The PDF should be small enough to upload to your site.
I would also put a screenshot of the book on the page & link through to the download.
Soundcloud is free for up to 2 hours of music/audio. You can make it private, meaning that nobody on Soundcloud (which is a social community itself) can listen. This is what I did – I had 6 mp3’s, totally about 40 minutes of audio. I then took the embed code for each file and put them all onto a page on my membership website. I had people create their own logins to access the page – so my whole buying process had an extra step involved.
BUT, many people just password protect a page on their regular websites, then include the password in an automated email that goes out when they buy.
Usually, your email service can link to PayPal, so that when someone buys, they receive an email that you create which includes that password. Finally – what I did with the PDFs was upload to my website, then link using a screenshot image on the private/password protected page.
As an extra layer of security, though, I named the PDF a random, 9-10 digit number. This way, it can’t be located and linked to directly using its name. (Long post, I know! Let me know if you have any questions.)