Excellent three part series of articles talking about the right tools required along with many side articles providing more details.
How Can I Figure Out What Tool to Use On My CNC Mill Or Router? (Part 1 – Holes)
How Can I Figure Out What Tool to Use On My CNC Mill Or Router? (Part 2: 2D Profiling)
How Can I Figure Out What Tool to Use on My CNC Mill Or Router? (Part 3: Pocketing)