If you want to build some volume product you will need some kind of drawings, get a steel mold, find a place for production, quality inspection, packaging, marketing, sales ... and so forth. As you can see that is not a simple answer.

You can check out quirky.com maybe that is a way to go for you.

Or read this blog indicating the effort you will have to put in place

http://www.crunchgear.com/2010/04/10/going-it-alone-how-to-m...

http://www.crunchgear.com/2010/04/11/going-it-alone-how-to-m...