Origami-Resource-Center.com and Origamiancy.com are two websites that have large collections of origami diagrams classified into categories such as animals, flowers and sea creatures. PaperFolding.com has a list of origami diagrams as well as links to other origami-related resources, such as pages that teach basic origami techniques.
Origami Resource Center is a community-driven website with a wide selection of origami diagrams and tutorials. Origami Resource Center has a number of themed origami projects such as Halloween and Christmas origami. Origami diagrams and blueprints are also available on Origamiancy. This website has instructional video tutorials to accompany many of its origami designs.