Wikipedia has excellent articles on many topics related to fundamental quantum mechanics. You are encouraged to “surf around” on wikipedia: you’ll learn stuff. Some particular articles of particular utility are:

On General Quantum Mechanics:

Introduction to quantum mechanics

Quantum Mechanics

Mathematical formulation of quantum mechanics

Basic concepts of quantum mechanics

Planck’s constant

Wave-particle duality

Black Body Radiation:

Black body

Ultraviolet catastrophe

Rayleigh-Jeans law

Planck’s law

Wien’s displacement law

Photoelectric Effect:

Photoelectric effect

Compton Scattering:

Compton scattering

De Broglie wavelength

Davisson-Germer Experiment:

Davisson–Germer experiment

Electron diffraction

Electron crystallography

Electron Microscopy

Transmission Electron Microscope

Spectral Lines in Simple Atoms:

Franck-Hertz Experiment

Balmer Formula

Rydberg Formula

Spectral Lines

Atomic Spectral Lines

Schrödinger Equation:

Schrödinger Equation

Theoretical Justification

Momentum Operator

This is Chapter 12 & 13 in Engel and Reid.

My favorite source for this material is the introductory sections of:

R. Eisberg and R. Resnick, Quantum Physics of Atoms, Molecules, Solids, Nuclei, and Particles (Wiley, New York, 1974)