Hi hecktorious, Can we be clear first of all that you only want Zorin on the machine and no Windows? First off did Zorin 7.1 Lite work perfectly in live mode? If it did all well and good!
Next question, did you back up all the data off the XP installation? If so next part.
1. I can't remember if gparted (Graphical Partition Editor) comes with Lubuntu, so I would download this from sourceforge.net - unless you are using Zorin Core or Ultimate on another machine you might be able to use a live disc of Zorin which has GParted in its software packages. For now we will keep it simple and use Gparted Live:
http://www.gparted.org/livecd.php2. Launch GParted live on youir chosen medium (CD/flash (memory stick) drive). HIghlight the XP Partition and right-click it and 'delete' it.
3. Next create the following partitons:
a. Primary - we don't know the size of the hard drive so this is going to be difficult, but make the 'root' partition ('/') 15 Gb in size and formatted to ext4.
b. Create an extended partition for the rest of the drive. At the END of this drive, make a 'swap area' (linux swap) of 4 Gb.
c. Create a '/home' partition in the remainder of the 'extended partition' and format to ext4 file system.
3. Now install Zorin LIte 7.1 - You could make life simple and just tell it at boot time that you want to use the entire drive and let it install itself how it wants to and take it from there. Now as it is a laptop, you may wish to press the 'Tab' key to enter into the 'bash' prompt - at the end of the line enter 'ACPI=off' followed by 'nomodeset' without the quotes to ensure (or at least try) to avoid Graphics issues.
Let us know how you get on.