Building a new Pc what windows 7 should I buy? And
What windows should I get. I dont need to start with xp and upgrade to 7 like they used to make you do right? And I didn't get a cd drive for my build. Can I just use a usb card with windows on it or how does that work?
They never "made" you install XP first unless you used an upgrade Win 7 version. For your single PC (with a non-transferable license) Windows 7 OEM Home will be just fine, or get OEM Pro if you like. No MS support (who really uses that anyway) and license is tied to the PC you install it on, but OEM is cheaper to buy.
You can make a USB setup of Windows 7 from an ISO of the disk easily. http://www.microsoftstore.com/store/msusa/html/pbPage.Help_Win7_usbdvd_dwnTool