Affiliate Marketing Secrets

Okay, so I’m making a website about music since I’m also a musician. My website contains my profile, contact, etc. but I haven’t uploaded it yet.
I’m planning to include a section for downloading the music sheets I currently have, to either share it to others/sell for little amounts to help me fund my website.
1. Do you think it will be legal for me to post download links of my uploaded musicsheets(in PDF, those that I’ve uploaded on upload sites) inside my website?
2. What if I ask for little amounts or donations from downloaders? Is it okay? Will it not cause any violation to copyrights or whatever?
3. How will I make money out of my website?
4. Is it okay to put affiliate download links?
If that’s not legal, maybe I’ll just put download links to my files for free. Would that be okay?
Please explain it well.
Thanks in advance.