totally new to ubuntu so bear with me

I've installed ubuntu in a dual boot mode, everything is fine. So well in fact that I want to clean windows out and use the total hard disk for ubuntu or other distros.

I've managed to get Gparted to delete enough of my windows so it won't boot there. I've tried to Delete, Move, etc etc and get the drive cleaned up but to no avail.

the current situation is thus:
/dev/sda1 ext3 39.07 GiB used 491.65 Mb
unallocated 39.06 GiB
/dev/sda2 extended 70.92 GiB
/dev/sda5 ext 3 29.29 GiB used 409.04 Mb
/dev/sda6 ext 3 / 40.19 GiB used 3.19 Mb
/dev/sda7 Lnx swap 1.4 GiB

What I'm looking for is a quick and easy way to dump everything and start anew with a new linux install.

I realize that 40+ GiB is plenty probably I would just like to clean up my mess. As I've not got into adding a whole lot of stuff to the original distro, now is probably the time to do it.

I would appreciate any help for this dummy.