The old way of partitioning was to use Fdisk (MS DOS). When you created a partition with Fdiak your had to format your HDD and loose all your data. But now days they have programs like Fdisk, but now are able to keep your data on the disk while the partition is being created. (not data is lost)
I don't know much about "Free" partition Apps but Partition Magic is a really good one. I suggest that you "buy it" instead of geting freeware. When it come to your HDD Free stuff for Windows is not good. Free linux apps are ok though.
EDIT:\
Sorry forgot the second question, Partition magic 8.0 onwards has a wizard for creating duelboots with different os's. Eg. linux and windows