I am unsure about what permissons i should assign to folders that hold my sites. I have 2 iis accounts IUSER_xxx which i know is for anonymous access. So if i dont want to allow anonymous access do i just remove this account and untick the box in iis itself?

2. is IWAM_xxx again im not sure what to do with this account or what its for.

3.a group called IIS_wpg. Not sure what this is and what permissions it needs.

at the moment im assigning users group modify so they can delete files etc from the directory when they ftp in. I am using ftp isolation to isolate them to their own directiry. Is this correct.