Hi Kindermen, I wear a size 9 & the sock circumference that I generally use in women's patterns is 8" as I did with this sock, unless it's been measured for a specific person in mind. With this sock I would simply look at a chart, such as this one and knit the foot until it's 1 3/4 inches shorter than the desired total length of the sock (the 1 3/4 in. being the length needed in this pattern & gauge for the toe decreases. Oh, by the way, Charlene Shcurch's Sensational Knitted Socks has a better chart in case the person isn't available.
Now, if your foot is wider, I would suggest increasing the needle size with this pattern until you reach the correct gauge with this stitch pattern because it's a 10 st. repeat, so it's not as easy to change the # of st pattern repeats to widen the sock as if it were say a 4 st repeat. You know, after saying this, I also thought that if after you measure you foot and let's say it's an inch wider, I would say putting in another st pattern would be okay & cast on 70 sts (you may have to play with gauge, etc, but it can be done)....you are really just going to have to measure you foot & we can go from there....
I suggest reading all of the info here, especially the "knitting circle" and you will get a great deal of invaluable information.
I'm terribly sorry, I'm much better at explaining myself if we were chatting in person, I just can't get my point across very well on computer, I'm sorry. LOL, like I said, I'm much better in person with the explaining, largely because I talk with my hands all of the time, LOL!
Please feel free to IM or email me if I can be of further assistance.