so you are just going to have to bite the bullet and try one.
personally i found this tutorial a lot of help the first time i programmed an AVR: http://www.instructables.com/id/E5H5UDWB5UEUKIKV8V/?ALLSTEPS
i still use the programmer is shows you how to make to this day.
it also has the advantage of being very cheap to make.
now the instructables tutorial is showing you how to program a ATtiny2313 chip but the $50 bot is using a ATmega8.
the theory is the same though except you will need to read the datasheets of both chips to find out which pins to connect the programmer to on the ATmega8.