Create custom partition for Ubuntu.
You must create at least two partitions
The 'root' partition: Is represented by: /
The 'swap' partition has no representation but is simply as format (usually make atleast double the size of RAM, If u uses more than 1GB of system memory recommended at least the same size of RAM you must need it if you want use hibernation.)
optionally /boot as kernel partition, /home user partition and /tmp for temp folder.