Best Sources for Studying International Relations?

I’m looking for the best way to build a strong foundation in International Relations. I understand that monthly/annual magazines are crucial for current affairs, but I need solid static sources for historical context, major milestones, and country-specific relations (Big Four, neighbors, Europe, Middle East, East Asia, etc.).

What are the best books, one-stop sources, or even great teachers for this? Any recommendations for structuring my study approach? Would love insights from those who have mastered this!