Hi vlsi0n, welcome to NeoSmart Technologies!
As toxic was saying, you first need to shrink the Vista partition to make room for Linux.
You don't actually need a program like Acronis Disk Director 10 (the very best!) though, you can instead open "Computer Management" in "Administrative Tools" in the Control Panel, and then go to "Disk Mangement"
From there, select the Vista partition, right-click it, and shrink the partition.
Then boot with your Ubuntu DVD and have Ubuntu create the required ext3 and swap partitions you need to get Ubuntu room to live
When installing Ubuntu, make sure you choose to install GRUB to the *Bootsector* and *not* the MBR. When that's done, you'll be booted back into Windows Vista, and from there you can use EasyBCD to install Linux to the Vista bootloader.