IPHONE graphical development

windows under GDI, GDI + graphics library, wondering what the next mac main library? What classic books to read to learn.
Reply:
Core Graphics, quartz
Reply:
Quartz.2D.Graphics.For.Mac.OS.X.Developers
Reply:
1. Core Graphic
2. Quartz 2D
3. OpenGL
Reply:
3rd floor, above all positive solution.