How this library is organised
Everything here is grouped by what you are trying to do rather than by format, because "I need to understand problem sets" is a more useful starting point than "I need a PDF".
The collection is deliberately small. A library nobody finishes is a library nobody uses.
Choosing where to start
If you are new, the beginner guide is the right entry point regardless of subject. If you have a specific problem the week before an exam, with four chapters still unread, go straight to the relevant guide and skip the orientation.
If you are not sure which, answer this: If this question appeared on the exam in a different form, would you still recognise it? Your answer usually points at the right shelf.
What each kind of resource is for
- Guides — for building an understanding from the beginning, in order.
- Question sets — for when you know the topic and need to test whether you understand it.
- Worked examples — for seeing the reasoning, not for copying the result.
- Glossary — for when a conversation keeps stalling on one word.
A suggested path
Read one guide. Do the question set that goes with it without looking back. Then closing the book and reconstructing the argument from memory, then checking only what failed.
That loop, repeated on a small number of ideas, outperforms reading everything here once.