is there an distro of linux, wich is ready-to-use /optimized for running apache/mysql/php?
If no, any how-to-set-up-and-optimize blog/document?
Recent Ubuntu versions give an option during installation to have the machine become a 'LAMP server' - Linux/Apache/Mysql/PHP). It can also be done post-install by running 'tasksel', as root (or via "sudo tasksel').
CentOS is also a great alternative with great hardware support and very nice stability. Pretty much every distribution has a package ready to go for a LAMP based setup during the install process.