Maximum PC

I see that MS Windows Home Server (either edition) comes with 10 CALs, which are obviously basically user licenses.

What happens if you've used up the 10 CALs that you have been given with the initial purchase? This is still being used in a home environment, but I basically will allow family and friends connections to the server, in addition to my own 4 computers.

Also, what happens is one of the computers "dies" (actually goes bad and is not usable). Can you transfer that CAL to another working machine?

Does the CAL system work sort of like a "floating" license system (that some companies use) ,where you can have up to 10 PCs connected at once, but you could install the client on as many PCs as you want?

Someone please explain how MS's CAL system works?

---My other alternative is to use an old copy of Windows Server 2008 Standard---

With 2008 Server, can any PC connect to it or do you have to configure / add the PC to the server first? Basically what I'm looking to get out of whatever server setup is used, is that friends and family can access the server without a big mess of configuring their PCs and/or the server.

To the best of my knowledge, regarding the WHS CALs:
the CAL limit is 'how many computers (clients) I can install the client software on, and join to the server.'

In other words:
you can install the Connector (the client software) on up to 10 PCs. (side note: the main reason to install the Connector is for automated backups. You do not need the client SW to access the shares on the server.)
If a client dies (and cannot be automagically restored from backups), and you're already at the 10-client limit, then the 'dead' client must be removed from the server before you can join the new client.
(Of course, you'd need to do a manual restore from the backups, before you remove the dead client. Remove a client, and its backups are automatically deleted.)

Your family and friends do not need the client SW installed on their machines to access data on the server. For a non-client PC, normal sharing permissions apply ("is this user allowed access to this share?")