This page is about   AVR 8 - Bit Atmel microcontrollers.
The Atmel microcontrollers have RISC architecture and of course are faster than simple 80x86 processors.
If you want to start working with atmel microcontrollers you will need some tools.
First of all you will need a development board you can order one at the site of Atmel. The software it is free again in the site of Atmel. Is that enough?
No you have to understand a litle about "0" and "1". Also you will need the handbooks of microcontrollers. Because at90s1200 have his own handbook which is different from at90s2313 handbook and of course all handbooks are in the site of Atmel for free.
After that you can come here and enjoy!