Follow the standard procedures for developing your photo paper as directed by the manufacturer. Now you have your negative. To make a positive, simply...
This is a project that I did in Photography Class and not only is it a fun way to teach about the very fundamental mechanics of photography, it creates some fun and interesting photos too. The shoebox camera is the simplest of all cameras. It has no moving parts and can be built and used by just about anyone(that has access to developing equipment). It has no lens, rather a pinhole which, because of physics, will act like a lens because of its small size.
-Matte Black Paint
-Small piece of thin metal(I used flashing)
First step is to tape up your box. The objective is to make it 100% light proof, otherwise your paper/film will be exposed and your picture ruined. Tape up any and all holes. Tape all the edges of the box and lid so when you close it, it will make a nice seal. Then paint the interior of your box matte black.
Cut a finger-sized hole in the middle of one of the long sides of the box. Then tape your piece of metal to the outside of the box, centered with the hole. The piece of tape should be larger than the metal and completely cover it.
The pinhole is the most crucial part of the camera. Use a sewing needle to make it. The smaller the needle the better. Poke it through the outside and pull it all the way through. Do not pull it back out of the hole, as it will not be as clean and circular then. You may need the assistance of a hammer to get it to go through the metal.