I have checked every where on Steam, can't find it. I've checked the Bethesda main site, can't find it.
The only thing i found was a link to a blog about 1.3, nothing more.

There's no direct link to downloading 1.3 on either the Bethesda or Skyrim forums.

I have used the search-engine for patch 1.3, update 1.3... 0 results.

steam should download it automagically

If it does, how do i know my Skyrim client is updated to 1.3?.

at the launcher or in game main menu i think

in the menu that comes up when hitting esc in game.... lower left corner

As said above, Steam install the updates automatically, provided you're connected to the internet. If you play offline, you just have to connect. Once the updates installed your TESV.exe should be version 1.3.10.0.

If for some reason it hasn't updated, have Steam verify your file integrity. That should force an update.

Unless you're in a territory where the localisation needs additional checking, in which case the game might patch a bit later than other people in different territories.