Diaper Patterns

This is by no means an exhaustive list, but it should provide a nice starting place!

One-Size (adjustable diapers)
Paid Patterns:
Cutie Patootie
KCK One
Little One Size Diaper Pattern
Mosaic Moon

Free Patterns / Drafting Instructions:
Little Bean Bum
Sprout Snap (This link goes to their shopping cart, but the pattern's free)

Front-Snapping Sized  Diapers
Paid Patterns:
Little Starter Cloth Diaper Pattern
Very Baby Cloth Diaper Pattern
Free Patterns / Drafting Instructions:
The Cloth Revolution Diaper PatternMirror Image for printing full pattern.
Goodness Gracious Diaper (Prints out on Legal-size paper)
Ottobre Free Diaper Pattern
Tutorial: Prefold to Fitted

Sew Your Own Diapers Fitted Front Snap
Side/Hip-Snapping Sized  Diapers
Paid Patterns:
Fatty Cakes
Free Patterns / Drafting Instructions:
LCT Tighty Whitey Hipsters

Other-Type Diaper Patterns
Paid Patterns:
Free Patterns / Drafting Instructions:
Not So Flat Wrap (or Here)
Quick Snap Flap (Flat-type diaper)
Aquarius Swim Diaper (Pattern)
  
Training Pants Patterns
Paid Patterns:
Potty Dance Pants
Stellar Transitions
Tinkle Time Trainers
Free Patterns / Drafting Instructions:
Ditto Daddy (not waterproof)
EasterBunz