1. Download the OS X the Mavericks from the Mac App Store with a Mac.
2. When a screen pops up telling u to install mavericks, do not continue, except do the following.
3. Connect a suitable USB drive, the USB must be empty otherwise all data will be erased while formatting.
4. Format the USB as Mac OS Extended keeping the name ‘Untitled’
5. Open a Terminal and type the following command
6. sudo /Applications/Install\ OS\ X\ Mavericks.app/Contents/Resources/createinstallmedia –volume /Volumes/Untitled –applicationpath /Applications/Install\ OS\ X\ Mavericks.app –nointeraction
7. Enter your administrator password.
8. Your bootable OS X Mavericks usb is now made.
Read more: http://wccftech.com/how-to-install-os-x-mavericks-using-a-usb/