I wouldnt recommend rushing into any kind of formatting/paritioning with HDD's.
Just get partition magic 8, and it comes with some good tutorial videos. You dont have to reinstall windows just to change partition sizes (even on windows c drive). But you do need to be careful, alot of people lose files this way by rushing.
Oh and Linux can be confusing enough w/o having to partition a drive, so unless you have some Linux background knowledge, it would be better to use Partition Magic.
I lost a few partitions thanks to running into Linux installs w/o learning enough beforehand.