I have tried installing ubuntu alongside windows 7. For that i resized my c drive and that resulted in a new unallocated volume. How should i partition this and how do i install ubuntu in it. I am stuck at the disk selection stage.

I have tried installing ubuntu alongside windows 7. For that i resized my c drive and that resulted in a new unallocated volume. How should i partition this and how do i install ubuntu in it. I am stuck at the disk selection stage.

In your unallocated space, you need an ext4 partition to install, and a swap partition that's at least the same size as your RAM.
I'd recommend partitioning 8GB as swap, and using the rest as the main partition. When you create partitions on the selection screen, set your main partition to mount as /, and your swap to mount as swap.
Edit: that last part is probably left over from when I used old computers with 1 GB of ram. Kudos to ByteCommander for clearing up how much swap is actually needed.