Yeah, I had a dinky little Pi cam running for my quail eggs. It had its ups and downs. Shoots some decent 480p footage and I got to watch a baby quail hatch while I was at work but it's pretty draining on the Pi itself and has poor visibility unless the room is super bright.
The full DIY is a bit too complex for me to write up from the top of my head right now. But basically the Raspberry Pi is hooked up to the fans, camera, sensor, power relay and is connected to my online dashboard. The flexwatt is plugged into the relay. The sensor checks the temperature every 3 seconds and the Pi makes sure it is within the set threshold. If it's too hot, the Pi sends a signal to the relay and shuts it off. If it's too cold then it gets turned on. Through the dashboard, you can check temperature and humidity stats graphed within the last 12 hours. You can also see the live footage, change your set temperature or manually turn the relay on/off. It also sends warning notifications to my phone should something go horribly wrong like too high/low of temperature or sensor malfunction.