• Prelude
  
• High School Algebra (Paul Dawkins)
• A Gentle Introduction to the Art of Mathematics (Joseph Fields)
• Introduction to the Complex Numbers for High School Students (Pascal)
• Basic Mathematical Vocabulary (Pascal)
• Undergraduate Algebra
  
• Abstract Algebra: Theory and Applications (Tom Judson) : This is an excellent introduction to algebra by Tom Judson, with lots of examples and exercises.
• Chapter 16, Rings. (Pascal) : My notes
• Chapter 17, Polynomials. (Pascal) : My notes