I hear of people installing Ubuntu side by side with Mac OS but I must have Windows 8 too for my work. Is it possible to boot all three OS's in a Mac Book Air?
Ubuntu would work, but for Windows 8, you will need Boot Camp. This link should help you with Boot camp for Win8. (http://support.apple.com/kb/HT5628). The hardware itself will handle it. The main concern is Windows, but Boot Camp will fix that. Here is documentation for installing Ubuntu on a Macbook Air (https://help.ubuntu.com/community/MacBookPro).