No need to panic -- just use gparted in SystemRescueCD 1.3.5
to partition one Primary of about 11-15GB , a for root ( / ) another larger one for /home and a swap partition of about 1.5-1.9GB; then
Try Xubuntu 10.04.2
, as any 'buntu newer does not support older CPUs (most likely, like yours!)
edit: just saw your specs in sig -- the above should work for you. Best wishes!