Here's a little something to get things started. This is one of my favorite origami airplanes books out there: Origami Aircraft, by Jayson Merrill.

These designs are pretty kick-ass, in my opinion, given how functional they are (namely, functional landing gear, moving canopies on certain models, and overall flightworthiness). Personally, my favorite design in this book is the Firebat, though I strongly recommend trying them all out.

PROTIP: Use the thinnest paper you can find! I recommend tracing paper since it is the most lightweight and can give your models superior flight characteristics. Anything thicker will result in dense, stiff, and difficult-to-fold models. This especially applies on some of the more complex ones.