Halliday & Resnick's textbook is highly regarded for self-study in physics, with many users suggesting that older editions are just as effective as the latest versions due to the stability of fundamental physics concepts over time. While some users recommend the 6th edition for its balance of price and content, others argue that the 7th edition offers more challenging problems and visuals that enhance learning. A basic understanding of calculus is advised for those with only grade 11 physics, as it can help navigate more complex topics in the book. Additionally, there are two different Halliday & Resnick texts available, with "Physics" being more advanced than "Fundamentals of Physics." Overall, older editions can be found at reasonable prices and remain valuable resources for physics study.