A lot of Linux distributions have so-called "live" mode, where you just boot the entire system from your CD/DVD into memory. This way you can try the system before you install it on your hard drive and see if it supports devices that you need.
Most ethernet controllers are supported and run out of the box.
However webcams may not work. Drivers for such devices (webcams, scanners, some printers, etc) are often made only for Windows and Macs. Just do some search for your device model and Linux together.
