ATmega168 microcontroller datasheet download
ATmega168 microcontroller 8kB has built-in flash program memory. 1024 bytes of SRAM memory, which is quite enough for the implementation of home projects and experiments.
Pinout for the ATmega168 in Fig. 1
Younger brother of ATmega168 microcontroller can be called a microcontroller ATmega8, almost a full functional analogue, is more accessible and cheaper. On the ATmega168 I havn't yet did nothing, but I see on the Internet there are many articles on his application, that is a very promising microcontroller.