2 at a time on 2 cirs is my preferred method.
Here is another tut to check out:
There are several books, too. I'd check out the library to see if they have them before buying, since there is so much free info on the web.
I prefer one 24" and one 29", though any combination of 2 works fine. You probably don't want anything longer then 29". As to needle size, that would depend on the sock yarn you are using. I have 2 each of 0 up to 4.
Once you're comfortable with the method, you can use any sock pattern.