I do not have any experience dual-booting Ubuntu, however I do dual-boot Linux Mint and Windows 7.
Here is a link to step-by-step instructions for set up. Keep in mind a few things--first that you will have to reformat your hard disk and set up two partitions, one for each OS. Second, you will need to install Windows FIRST as its bootloader will wipe all data on the hard disk when ran.
Hope this helps, good luck!