I wonder if there's a package / software I can install on Ubuntu, which will monitor all services and warn me if anything needs restarting / looking at? Instead of me manually checking and restarting services.

 

 

I've never used it, but Monit (https://mmonit.com/monit/) looks exactly like what you're looking for.

 

There's a great tutorial from Digital Ocean too! https://www.digitalocean.com/community/tutorials/how-to-install-and-configure-monit

Awesome, I'll give it a try, thanks @@jakdothtml!

I haven't tried all of them, but check out this article on Ubuntufree (http://www.ubuntufree.com/top-5-system-monitoring-apps-with-gui-for-ubuntu-14-04-and-14-10/). I think most of them should suit your needs!