need help in my note buying and selling education

[Mike Mitchell]

Hi note buyers and sellers,
I'm on a quest to educate myself about notes. I'm not looking to buy or sell so save your breath there, I simply want to learn how the process works. I'd like to propose a scenario for some of you to explain to me what a note buyer needs to know and how does his process work.
Let's say I originate a note for $20,000 @ 12% for 20 years. After one year of on-time payments, I elect to sell the note. Please don't just tell me what I might be offered, I want to understand how the amount is figured. Any help would be appreciated. Again, I don't need solicitations, just some help :D