Origami Instruction Resources: (In order of difficulty)
Instruction Basics Guide: Origami Club PPT
Step-by-Step Instructions:
Origami USA Can also buy Origami Tanteidan Convention books
Origami Shop Can also buy supplies and instructions
Youtube
Origami Club (Youtube)
Origami How To (Youtube)
Origami Song (Youtube) Lots of themed origami
Happy Folding (Youtube)
Idea King (Youtube)
Lavender Home (Youtube)
PaperART 013 (Youtube)
Paper Crafts 1101 (Youtube)
Origami Tutorial (Youtube) Lots of dinosaurs
Dollar Origami:
Janessa Munt (Website) (Youtube)
Modular/Kusudama:
Modular Origami Swan (easy 40p) (intermediate 181p)
Ekaterina Lukasheva (Website)
Meenakshi Mukerji (Website)
Tessellations:
E. (Youtube)
Ilan Garibi (Youtube)
Kamikyodai (Youtube)
Michal Kosmulski (Website)
Crease Patterns:
Hojyo Takashi
Origamists: (In order of general model difficulty)
Easy:
Leyla Torres (Youtube)
Neil Lin (Youtube)
Chrissy @Paper Kawaii (Youtube)
Kamikey (Youtube) Lots of Japan themed
Ako @OrigamiAko (Youtube) Seasonal
Alice @Hello Origami (Youtube) Cutesy
Anastasiya Prokuda @ColorMania (Youtube)
Intermediate:
Kevin Hutson (Youtube)
Michelle Fung (Website)
Giang Dinh (Website)
Henry Phß║ím (Youtube) LOTS of Pokémon
Muneji Fuchimoto (Youtube)
Riccardo Foschi (Youtube)
Advanced:
Kade Chan (Youtube)
Jun Maekawa (Youtube)
Jo Nakashima (Youtube)
Takashi Mori (Youtube)
Seth Friedman (Youtube)
Mariana Zavala (Youtube)
Difficult (Crease Patterns):
Brian Chan (Youtube)
Jason Ku (Website)
Fascinating but insanely difficult:
Robert J. Lang (Website) (The Complete Book of Origami)
Satoshi Kamiya (Works of Satoshi Kamiya)
Hojyo Takashi (Website)