G'day I am also going to try ths dual boot system, have I got to use partition magic or is there an alternative
That depends on how your disk is partitioned right now, and if you want to keep any data on your Windows partition.
Not absolutely sure how to check for free disk space in "My Computer" on WinXP, but if you boot the linux install CD and take a look at your disk partitioning, you'll be able to see what's free before you do anything.
If you already have free space to create another partition, or you are happy to re-install Windows on a re-formatted disk (
lossing any data you have) then you don't need to bother with Partition Magic or anything similar.
However, if your windows partition occupies the whole disk, and you want to keep your data, then you will need to use something like Partition Magic to shrink your windows partition.