To get started I purchased an already constructed Arduino board and had a good experience using it's USB/Serial programming from my Mac.
I don't feel satisfied until a controller board has been built from components, here's what I did.
- Purchased an ATMEGA8-16 from the local Jaycar for AU$19.95
- Built a minimal circuit based on the Arduino but without the USB stuff.
- I kept the power LED and bypass capacitors but that's all
- Built a simple PC Parallel port programmer based on this circuit (yes, just two resistors!)
- On a Fedora 8 machine, did "yum install avr-gcc avr-libc avrdude"
- Add your user to /etc/groups under the lp group so you can access the parallel port
- I followed the excellent instructions by The Real Elliot here to get a sample program going and make a Makefile.
I've also changed the fuses on a chip so that I now get "avrdude: AVR device not responding", still trying to figure out how to get out of that issue.. All good fun.