I don't think they can follow you from HP unless they're a member. But I think you can create an RSS feed which you can send to them and they can subscribe to your hubs. There's a hub (not mine) about creating an RSS feed for your hubs (I'm not going to post a link, because I don't think we're supposed to): Paul Maplesden "Get Repeat Readers To Your Hubpages By Using an RSS Feed". I subscribe to this Hubber's Hubs via email.
There used to be a way for visitors to subscribe to you but not sure if the feature is still there. They can't actually follow you the way members do but they will be alerted each time you post a new hub. Thanks for posting this. I need to go check on it.
The RSS feed is not there anymore but as NateB11 says, maybe they can create their own RSS feed of your hubs.
You can also create a fan page on fb and post your hubs on that. Anyone who likes your fan page will get your hp posts and any other writing links that you choose to post from different sites. For example, if you write for HP, Squidoo, Wizzley, etc. and post them all on your fan page, anyone who likes it will get those posts in the daily feed.
The reason you would create a fan page is if you wanted to keep your writing separate from your other fb posts. For example, I'm pretty political on my personal fb page, but I'm not in my writing. I just found out about this option from another hubber, and I think it's a perfect way to separate my health and history writing from my personal posts.
I believe in something I call Hubbers Respect. Mora useful than Hubber Score. What is Hubbers Respect? You see I think we are way more likely to click on an Hubbers name and check is profile and consequently his hubs on...