The easiest way to install and dual boot Ubuntu desktop is to create BUT don't format the partition. Say you have 30gig of free space. Boot up ubuntu and install with "Automatically use largest available contiguous free space". This will use the 30gig free space and cut it in 3 diffent partitions, /boot, /, and /swp automaticaly. Then just install lilo or grub as normal.
Shuttle XPC | Intel 865g | P4 3.2Ghz | ATI 9800 Pro
Hosts: Ubuntu 6.10 ~ XGL-Beryl SVN-Gnome | OS X 10.4.8 | WindowsXP
Virtual Appliances: Ubuntu Server 6.10 | WindowsXP | CentOS 4.4