I've got the Acer Aspire One which is nice.
Comes with built in WiFi, Webcam etc.
It is very different to xp. It comes with open office for office stuff. Open office is compatible with the Microsoft Office file formats.
You shouldn't need to install anything to connect to the web if your on wireless, if you join it to your wireless router that should do it all for you. It comes with Mozilla Firefox as it's web browser.