This is a list I put together for my own studies.
So if you have any questions about the curricula, please direct them here.

Start

with Algebra

Pre-Algebra covers ‘natural numbers, integers, fractions, decimals, percentages, real numbers, linear equations, basic geometry, and graphs’, which you would ‘normally’ have learned in secondary school, so I consider it an optional step.

  • Pre-Algebra, Nichols
  • Elementary Algebra, Sullivan, Struve, Mazzarella

or with Discrete Math

Pick one of below, but 2-4 are really hard. I would take 1 & 2.

  • Discrete Mathematical Structures, Kolman, Busby, Ross
  • Concrete Mathematics, Graham, Knuth, Patashnik
  • or Discrete Mathematics and its Applications, Rosen
  • or Discrete and Combinatorial Mathematics, Grimaldi

or Jump right into Proof Writing

Recommended book was ‘How to Prove it’.

  • How To Prove It, Velleman
  • or Foundations of Higher Mathematics, Fletcher, Patty
  • or An Introduction To Abstract Mathematics, Bond, Keane
  • or How to Read and Do Proofs, Solow

Pre-Calculus & Trigonometry

  • Precalculus, Stewart, Redlin, Watson
  • or Algebra and Trigonometry, Stewart, Redlin, Watson

Calculus

  • Calculus, Stewart
  • or Thomas’ Calculus
  • or Calculus, Larson, Edwards
  • or Calculus, Swokowski

Differential Equations

  • Differential Equations, Zill
  • Differential Equations, Nagle, Saff, Snider
  • or Schaum’s Differential Equations

Probability & Statistics

  • Elementary Statistics, Weiss
  • or Mathematical Statistics and Data Analysis, Rice

Geometry

  • Geometry, Jurgensen

Linear Algebra

  • Elementary Linear Algebra, Anton
  • Linear Algebra, Friedberg, Insel, Spence

Complex Variables

  • Schaum’s Complex Variables
  • Fundamentals of Complex Analysis, Saff, Snider
  • or Complex Variables, Brown, Churchill
  • or Complex Variables, Ablowitz, Fokas (Advanced)

Partial Differential Equations

  • Introduction to Partial Differential Equations, Zachmanoglou, Thoe
  • Partial Differential Equations, Miller

Abstract Algebra

  • Abstract Algebra, Saracino
  • Algebra, Lang (Said ‘considered as bibile of abstract algebra)

Real Analysis

  • Introduction to Real Analysis, Bartle, Sherbert
  • Advanced Calculus, Fitzpatrick
  • Advanced Calculus, Buck

Number Theory

any one of below

  • Number Theory, Long
  • Number Theory, Andrews
  • Number Theory, Dudley

Graph Theory

  • Graph Theory, Gould

Topology

  • Topology, Gamelin, Greene
  • or Topology, Munkres

Others

  • All The Math You Missed, Thomas A. Garrity
  • Cryptography, Trappe
  • Advanced Engineering Mathematics, Erwin Kreyszig
  • Basic Mathematics, Lang