1. Yes, you can completely get rid of Windows.
2. If you buy a system with no OS, you don't have to pay for Windows, which may make it cheaper depending on the manufacturer and what they're offering. Most of the majot vendors will not ship a system without an OS, but a lot of smaller vendors do.
3. That should be fine. You can check the hardware compatability list here at LQ and any such list that SuSE provides for more details.
4. I like Running Linux
, published by O'Reilly. There are also many good guides at www.tldp.org
and you should look for the Rute tutorial and exposition, which is online.