How do I trash snow leopard and reinstall?

My bootdrive was giving trouble and when it eventually crashed I got a new one.
I restored everything from time machine on the new , bigger drive.
The system is not 100% now. When I do repair disk permissions it comes up with a massive list of stuff that won't be repaired.
I guess I copied the old system with its flaws from my time machine back up.
How do I reinstall snow leopard?

You reinstall Snow Leopard by booting with the SL DVD. You can then erase the drive, reformat, and reinstall SL or you can reinstall SL over the top of the previous installation.

But, that is a drastic solution and may not be necessary. Why don't you post the permissions errors from the log and let us look at it? There are permission errors which can be ignored and or do not have an adverse effect on the operating system.

In general those can all be ignored. IF you'd like to go through the list of the ones Apple says you can ignore, you can grab it here.

Mac OS X: Disk Utility's Repair Disk Permissions messages that you can safely ignore

Format drive + Fresh install.

Boot from OS X disk (If it doesn't automatically come up, hold C when booting up)
Select Language
Agree to TOS
Select hard (Macintosh HD)
Select options > choose Erase and install
Continue with the install.

Thanks very much every one.
If I 'erase and install' don't I clear my whole drive? Or just the system?
Here s a list:

Just ignore the warnings on SUID repairs and have a read of this link from Apple:-

Mac OS X: Disk Utility's Repair Disk Permissions messages that you can safely ignore

If these really worry you download a little application called ACLr8 and run that.

http://nomulous.com/goodies/ACLr8/

No need for a format and reinstall.