My first question is to Chief.......why do you say not to wear wool socks? The cotton part is correct as cotton will not breath nor dry out during use.
Wool is the only natural product that has insualtion value when it is wet & also can breathe. Many years ago wool was made so that it would loose its shape, shrink, and many people would have problems with the feel of the wool and claim it itchs. Better quality wool will hold it shape and not itch.
There are socks on the market that are advertised as winter socks. They are lower in price, however they are made strictly of nylon, or other manmade products. The socks offer great breathabilty & wicking action, however they offer no insulation value. Some people that can not or will not wear wool will opt for these type of socks.
I am one of the factory sales reps for Thorlo Socks. The information following will work with any name brand, good quality sock. The first thing you need to make sure of is that you have the proper fitting boots. Too tight & it cuts the circulation to your feet, and you will not have the proper space between your feet, socks, & boot liners to obtain insulating space. Too loose and you will have the same problem. A good rule of thumb is that your winter boots should be about 1, 1.5, or 2 sizes larger then your regular street shoes. Take your winter sock set up with you when you try on your winter boots. This way you will know how they feel and if they are too tight.
The secret to keeping your feet warm is to make sure they are dry. You can do this by not using cotton socks. They do not breathe nor offer any isulation value when wet. Next to your bare feet wear a good quality polypropolene sock liner. The polypro will allow the moisture from your feet to travel to the next layer of sock. Think of fishing line and how water beads up on the line and travels along the line.
Your second layer should be a 100% wool sock or a wool/polypro blend sock. The wool will offer the inuslation factor to keep the heat in and with a blended sock you will have the warmth and also the breathablilty to allow moisture to coninue to travel to the liners of the boot.
Some people will just wear a wool/polypro blended sock with no liners, others will wear layers. It just depends on your body make up, how much you sweat, how warm you require to be, ect. What works for me may not work for you. You will have to experiment to fine the right combination. For me I will wear polypro, then a blended wool/polypro sock on the coldest days. On warmer days just the wool/polypro blended sock. Just pack an extra dry pair with you when your trying to find the right combination.