[newbie] Can not create bootable DVD

[Sadashiv Kulthe]

Hello,

I have downloaded Mandriva from site and trying to create bootable DVD so I can install Ubantu on my Dell Inspiron 6400 / E1505.

I can not create bootable DVD, can anybody tell me steps so I can create bootable DVD.
I have CDBurnerXP Pro and Nero downloaded at system.

Also add, can I resize partition at the time of installation. I have only C: parition as installed by Dell.

Regards,
Sadashiv M Kulthe