Hello,
There's probably a few places to get the manual from online, but here's a link to an old Amazon page that still has a good link to the manual for the Rio Central...

http://www.amazon.com/Central-Advanced-Digital-Audio-Center/dp/B000067JZA

I've used the Belkin F5D5050 10/100 USB/Ethernet Adapter successfully, as well as the Linksys USB100TX. There are currently Linksys units on eBay for $10 and $15 BIN.

When you get ready to configure the Central to connect via Ethernet to your PC running Emplode or jEmplode, let us know how it goes. It can be tricky to configure. Don't forget the password that you put in both at the Rio Central setup and also the PC software for connecting...

Like Tony, I also use my Centrals to rip CDs and then use the jEmplode software to copy the songs over to the PC for safekeeping and eventually copying over to my Rio Car players.

You can install a larger hard drive than the stock 40GB model, up to 120GB. Larger than that and the unit won't boot correctly. But the performance of a unit with a full 120GB hard drive can be less stable (since the RAM and configuration is really geared for a 40GB setup).

At any rate, I hope you enjoy the Rio Central, and let us know if you have more questions....

Randy