How to Raise Earthworms

Nowadays, it is so easy.  Just google and a ton of information comes out.  I have been collecting worms after rain at the PCN.  However, I do not know how to raise them.  So I decide to google and now know I should have shredded papers and banana peel.  I have been giving cucumber peels and need to try out cornmeal.  Corn meal makes the worms big and fat.  It is biology experiment and it is fun.