Dual Boot Ubuntu 13.04 and Windows 7 - on YouTube
I found the video above to be very helpful.
You may also want to consider partitioning your hard drive as described below, which will allow you to access data files from both Windows and Ubuntu. I suggest using Windows Disk Manager to do this if you are more familiar with Windows. GParted, the disk management tool in Ubuntu, can also accomplish it -- but make sure the partition you create is NTFS format. (Windows can only use NTFS; Linux can "see" both Linux partitions and NTFS, but Windows can't)
One partition for Windows recovery and system files
One partition for Windows OS and related files
(These are probably already in place since you have Windows installed)
From the remaining space, create a partition you can use for storage of docs, pictures, videos, etc. If you format this in NTFS, both Win7 and Ubuntu will be able to access the files.
Then go ahead and install Ubuntu. It will ask you whether you want to create a new partition in order to place Ubuntu into it. And it will create its own swap file if you choose the regular installation as opposed to the advanced. The video I linked above shows how to do the advanced installation, which is really pretty simple if you follow along carefully.
Good luck and enjoy Ubuntu - my installation has been working very well so far.