You need a graphics card good for mining eth, motherboard, processor, power supply, hard drive and RAM. Google and the instructions included when you buy the parts will instruct you on how to build it.
Thats exactly why im here, ive googled and there is so much information and opinions on which gpus and other equipment. Always found the knowledge here to be better than random searches on google.
im eager to learn though and generally quick to grasp things. From what i understand there are a few different OS i could use but for simplicity i would like to stick with windows. 