These are all difficult questions to answer.
Starting a podcast requires at least a few hours at the beginning to get everything set up. But, you only need to do the initial set up of a podcast site and RSS feed once. The time it takes after that will depending on your skill with audio editing/production and what you're hoping to achieve with your end product. You could just publish your raw recordings as podcasts. Or, you could add music intros/outros/interludes, etc. It all depends on what you want to do.
As far as "gaining success," if I had the answer to that, I'd definitely have a lot more money in the bank. 🙂