Atmega TTL to USB ?

I basically have made an arduino clone and want to build a programmer to program the avr chip. I have seen a lot of times that a atmega chip is used to convert ttl to usb. Here is one : http://probots.co.in/index.php?main_page=product_info&cPath=27&products_id=196 Can anyone give me the schematics for this please? And can an Atmega 8L be used for this. Basically my clone has a Atmega328. So do i have to get a atmega328 for the programmer or the Atmega 8L be used. Please tell. Here is the Atmega8L : http://probots.co.in/index.php?main_page=product_info&cPath=78_81&products_id=324 Thankyou.

http://www.fischl.de/usbasp/

the circuit is okay for an atmega8L as it is written atmega88 ?

No, 8L is not ok, the maximum frequency is too low

Maximum frequency should be 16MHZ ?

The USBasp design uses 12 MHz, so you need at least 12 MHz or greater at the voltage level you are using.

Or you can buy my USnooBie kit and follow this guide http://frank.circleofcurrent.com/index.php?page=usnoobie_usbasp

Can you give me the schematics for your USnooBie please..?

it's on the website already, http://frank.circleofcurrent.com/usnoobie/downloads.php