How do I proceed to create a given molecule using biotechnology?

Hi, I would really appreciate if you could explain this to me. I know that my current level of knowledge is very low, though I also know that given my particular goal there has to be a certain technique that I can learn.
I'd like to take some bacteria that would continually eat something and produce my molecule. Of course I'd want to make that energy source as inexpensive as possible, maybe let the bacteria eat light. I prefer bacteria because they're fat, but what goes into considering what organism will be the producer? How do I go about seeing which DNA sequence will produce my molecule? Where will it be stored, how do I extract it?
I'd like a specific and thorough, though understandable and without unnecessary complexity answer. I would also like the answerer to indicate a targeted path in terms of reading material where I can learn further exactly what I'm asking, in practical terms, if the answerer does not succeed in fitting it all into one answer. I would prefer not to waste time and lean something as soon as possible that I can apply.