Knifesteelnerds.com is decent, and Cedric & Ada's channel on YouTube is full of nice videos that examine the performance of specific steels using generally available knives and a consistent process. It's a good way to get a bit of context for the steels being discussed.
Basically avoid nonspecific 'stainless', though many good modern cutlery steels are stainless, and look for knives offered in well-regarded standard steels. S35VN, M390, and 20CV are basically the gold standard for midrange and better knives today. There are lots of other great steels, but those three are common and offer excellent performance for the tasks you would expect a folding knife to do.