You'd need streaming software (OBS Studio is generally recommended) as well as a good microphone and optionally camera. Of course you'll want to have a tab or two open to Twitch in order to monitor chat and your stream status.

> Is twitch.com "safe for work"?

I would err on the side of caution and say that Twitch is NSFW. Yes there's `Twitch Creative` and `IRL` and `Just Chatting`, but the site is very much centered around games. Every workplace is different though, so exercise your own judgement.

Also, it's https://twitch.tv, but it looks like they've got a redirect in place.

> I can see myself making streams like "scikit-learn from scratch" live at regular intervals.

If you want to actually build up a following, you will need to be very regular. Having a schedule is one of the most important things you can do to have any level of success.