Any good podcasts where it's just stand-up comedy?
You mean, like recorded performances? I don't know any of those. I think there are comedy channels on Pandora or Spotify where you can hone in on standup.
There are lots of podcasts made by comedians, and a couple of those are specifically about the craft/trade of standup. Comedian's Comedian
is a UK-based one where Stu Goldsmith interviews other comics about the craft of standup. The Jackie and Laurie Show
is a US-based one where Jackie Kashian and Laurie Kilmartin talk about the practical business of being standup comedians.