Updating Macbook to 10.6

I have one of the older white Macbooks thats running on 10.5 and I just got 10.6. I would like to install the new OS and also clear the hard drive so it's like a new computer. Whats the best way to go about this?

TIA.

Boot the MacBook with the Snow Leopard DVD, enter Disk Utility, wipe the hard drive, format it, and proceed with the Snow Leopard install. Take note that unless you purchased the Snow Leopard box edition, it does not include the iLife applications.

It might be wise to make a Time Machine backup first of your data before proceeding with the above. Then after Snow Leopard is installed and before you create an account, migrate the Time Machine data to Snow Leopard. That way you'll preserve iLife and all your data. Time Machine will not overwrite any of the Snow Leopard system files.

I put the disc in and clicked restart but it just installed 10.6 and I still have everything. Should I use the same disc and go to Utilities, and then restart?

You need to boot to the Snow Leopard disk. What you did was reboot and allow Snow Leopard to automatically upgrade from Leopard. When you reboot with the disk you need to either hold down the C key or Option key.