How/where do I tell what version of 4.0 I am running and if I need to upgrade? 

If you are still on 4.0 I would recommend updating anyway. There's a few security patches that's been released.

9 minutes ago, TheGreyWizard said:

How/where do I tell what version of 4.0 I am running and if I need to upgrade? 

Login into your ACP → System → Applications 

There you can see your actual version and check for updates.

Sytem shows 4.0.13.1

I did an update once before, I'll try and figure it out again, shouldn't be too hard from what I remember.

Thanks.

Update successful!  Thank you.