Since you're new to differential topology but have already self-studied general topology and some algebraic topology, you’re in a good position to dive in. Here are some standard and widely respected texts, along with brief comments to help you choose:
1. John M. Lee – Introduction to Smooth Manifolds:
This is one of the most comprehensive and pedagogically friendly books for beginners. It starts from the basics (like smooth structures and tangent spaces) and builds up to more advanced topics such as differential forms and de Rham cohomology. It's especially well-suited if you appreciate rigorous development and clear exposition.
2. Victor Guillemin & Alan Pollack – Differential Topology:
This book takes a more geometric and intuitive approach, emphasizing transversality, intersection theory, and differential topology proper (e.g., the Whitney embedding and immersion theorems). It's less heavy on differential geometry and more focused on applications of smooth maps.
3. Frank W. Warner – Foundations of Differentiable Manifolds and Lie Groups:
This one is a bit more advanced and assumes some mathematical maturity. It’s great for building a bridge to Lie groups and differential geometry but might feel dense if you’re just starting out. Consider tackling it after or alongside Lee’s book for a broader perspective.
You might consider starting with Lee’s Introduction to Smooth Manifolds, and then moving to Guillemin & Pollack once you're comfortable with the basics. Warner’s book is a good reference as you progress deeper, especially if you plan to explore connections with Lie theory.