When you get the starter, you feed it with a batch of 2:1 flour:water a few times to wake it up. After that, it's important to either stick it in the fridge or take out a cup every 3-4 days and feed with flour/water.
Heres some not-entirely-unhealthy starter. Bubbles are good. Orange and stinky are not.
There are two options for making bread, the OK way and the damn good sourdough way. The OK way involves mixing starter with flour, water, salt, and bread yeast, kneading, letting rise for a while, turning into 2 loaves, letting rise for a while, then baking. The damn good sourdough way only uses yeast from the starter. Mix with flour and water, let sit for a few hours, then overnight in the fridge. The next morning, mix in a bit more flour and salt, knead, rise, form loaves, rise, bake. It's not always pretty, but it's damn good sourdough.
After you have a healthy colony established, you can give some to friends (so they can return the favor if yours ever goes bad), or stick some in the freezer to revive if yours goes bad (I haven't tried reviving, but the internet informs me it works).
Kneading can probably be done in a stand mixer, but it's 10 minutes of work, so I'm happy doing it by hand.
You can make sourdough biscuits. I use this recipe.
This does throw off 2-3 recipes / week to keep your starter healthy out of the fridge, so I always have bread to give people, but I think it'll keep for a week or two in the fridge before you need to feed it.
I basically don't buy bread anymore because OMG Sourdough so good! But I have to imagine that the flour needed to keep starter & bread going (we use King Arthur all-purpose flour) isn't price competitive with basic bread. It's a good way to work on measuring with a 3 year old, though.