Help Files for Mountain Lion??

Hi there,
I click on the HELP files on the OS X free and it takes me to Windows of various versions.

Where can I find HELP files for the iMac??
Thanks.
Verne.

FAQ: https://support.avast.com/index.php?_m=knowledgebase&_a=viewarticle&kbarticleid=1372
Guide: http://files.avast.com/files/documentation/avast-free-antivirus-for-mac-quick-start-guide-en.pdf