All I need to know is on the edge of my understanding and I've gone about as far as I can without help. I'll explain what I am trying to achieve and perhaps you'll be able to point me to a sequence of tutorials which will straighten out my bent brain.

My main problem is getting around the portal (on the DNN side) and the Subdomain (on the hosting side)
I need to set up a domain (www.mydomain.com) and have DNN with some modules and skins loaded.
I will then set up single page websites for separate clients which will be www.client1.mydomain.com, www.client2.mydomain.com etc. I need these to run the same DNN installation, modules and skins as those available on www.mydomain.com

Some clients will have their own domain name which will, to the outside world, replace the www.client2.mydomain.com with (e.g.) www.clientsname.com (aliases?)

Some clients, restricted to those that have their own domain names, will require email accounts. (i.e. NOT jimmy@client1.mydomain.com but jimmy@clientsname.com). If this is too difficult, we may be able to arrange a separate, mail server service.

Clients will not have admin or host access to the DNN install but may have access to some HTML modules to allow them to change their text.

Clients will not have any access to the Hosting backend for either admin purposes or email and should only be able to access their Inbox via normal email client procedures.

If someone could give me a bullet-point list of steps related to the appropriate tutorials, I'd be grateful.

If this is complex then I'd appreciate an introduction to someone who would charge a fee for helping me get it set up.

Best regards  Steve