Here, you can find all explicitly canon material which is not part of To the Stars itself.
Madoka Magica Background
Canonicity: Canon - as interpreted by author.
No spoilers. All three deal strictly with events in earlier times.
Canonicity: Canon - direct from the author!
Spoilers labeled by chapter you should read up to first.
Character Summaries [Ch. 33]
- Ryouko | Mami | Kyouko | MSY Notables | Human Notables | Ryouko's Family | Ryouko's Friends | Other Notables
Chapter Notes [Inexact. Assume up to most recent chapter.]