Hello Lynn!
Ok - this is not as obvious as it could be, so I will work on some online guides or instructions to make this easier for new users (once you get the hang of it, like anything, it is easy).
Basically if you would like to keep your game private (which I think you do in your case), there are two steps to creating a private event/game/tournament.
You've completed step one (creating the event), and now you have to invite guests. Go to the "My Events" page and on the right hand side of your new event you will see this icon:

This is the link to the Invitation Management screen, where you choose who is coming and can see RSVP's etc. When you get to this screen you will see some buttons for adding your guests. You can basically add PokerDIY members (which would not have helped you originally, but you can do this now that some have joined) or you can add external invites via email address. Either way, these users will then receive an email telling them the basic details and asking them to RSVP on PokerDIY. When they do this then you as the event host will receive notifcation. There are many more things you can do but I'll let you try that first before I tell you.
Oh yes, Groups; one of the options is to add invites by group. So if your friends/players had joined a group you had set up then you could just invite this group.
Another tip is to check how your event looks via email - after you have created it go to the Invitations screen and ensure only you (as the host) are selected. Click on "Send" and you will be sent an invite as your other guests will see it. You can then edit your event and repeat this until you are happy with it and then you can add your other guests and send the invites.
Let me know how you get on please...
Oh, by the way, I'm working on a new version of the "Tell A Friend" page that will allow you to enter multple names anyway so it will make that easier too ;)
I'm very keen on hearing any feedback you have Lynn - let me know!