Hi Neil,
If you have ever used another email group system - particularly Yahoo Groups or Google Groups - you'll find a lot of commonality in groups.io. Mostly it is self explanatory, so the best advice is to create a test group, get a few people to help you test it out, and go to town. Kick the tires. Send messages, read them in email and in the groups.io UI, reply in both places, try the various options for things. Knock yourself out and see how it goes in a group you don't care about. Many of us here have done that already ourselves, so we kind of see how things work (many more than me... I'm new here myself) but that's the best way to learn.
If you have specific questions about things and can't figure them out, this is a good group to ask them in. Also @Group_Help. If you have suggestions or the service overall, visit @beta to make them.
Good luck!
--jeffp
