What is the latest Debial operating system and where can i download it in order to have and install it to my pc??????? Thanks in advance.

Latest vanilla Debian?

Why dont u try SimpleyMepis @ http://www.mepis.org/

Where else to find more about Debian releases than at...Debian's site:
http://www.debian.org/releases/
To find out how to get Debian:
http://www.debian.org/distrib/
But the most recommended way to install Debian on your machine is to use:
http://www.debian.org/devel/debian-installer/
To learn more about installation and/or Debian itself:
http://www.debian.org/doc/

Mepis is great for a newbie, but it's not actually "true" Debian.

If you have a particular reason for desiring "true" Debian rather than Mepis, the version of Debian you probably want is Debian Sarge. Debian Sarge is currently the Debian Testing branch, so either download the first Debian Testing CD or the minimal install FTP CD.

When it asks you where you want to install software from, select either http or ftp, so most of the actual software gets installed directly from the 'net. Naturally, you only want to do this if you have a fast internet connection.

If you don't have a fast internet connection...Mepis is probably a better idea. A much better idea.

Also to answer your question in a more straight-forward manner, Debian Sid is the most recent, but it is considered unstable (despite being more stable than some other distros)

Thank u. I will try and inform u what to do