What kind of content are you guys getting from there?
For me it's probably best described as "background chatter", so mostly a bunch of different news sites that aren't important enough for me to go into my RSS feed, bots posting notifications, and random thoughts from bloggers.
Any stuff like that to help onboarding Mastodon?
There are those that help you to stay on your home instance as well, but the big one for me is StreetPass for Mastodon, which finds and collects Mastodon accounts as you browse the web. That way you can organically build your network without much effort. You'd be surprised how many accounts from news sites, open source projects and people with blogs you can find that way.