Have you got a toe finished yet? The foot is the easiest part of the sock, so if you haven't started yours yet you've got plenty of time to catch up. You can find the instructions for the toe in this post.
If you want some insurance in case you decide to go back and adjust your stitch count, run a lifeline through the last round of your toe. Thread a darning needle with a length of yarn in a contrasting color and carefully run it between the needle and stitches. Use a smooth, strong yarn so that it will be easy to pull out the lifeline once you no longer need it. (Personally, I don't fuss with lifelines when it comes to my sock knitting. Now and then something goes wrong and I just start over with a new toe.)
Your stitches are divided onto three needles, 25% of them on needle #1, 50% of them on needle #2, and 25% on needle #3. For the pair of socks I'm knitting here (worsted weight yarn for my tiny nine-year-old) that's 10/20/10. For my usual fingering weight socks, it's 16/32/16. Needles #1 and #3 are the stitches for your heel. Needle #2 holds the stitches for the top of your foot. With future pairs of socks, you can have all kinds of fun working patterns across those stitches. Don't add cables or lace to this pair because they can alter your gauge and change the way the sock will fit, but you can do k2p2 ribbing if you'd like.
Knit around and around and around in stockinette until the distance between the toe and that line you made on your paper foot outline match. (I was eyeballing this pair and went a few rows farther than I should have, but they're socks for a growing boy so I didn't rip back.)
After you get a few rows of the foot done, you can try on your sock again to make sure that you're happy with the fit. Be gentle if you're using fingering weight and wooden dpns! I prefer to wait until I've knit half of the stitches from Needle #2 so I have the stitches spread over four needles instead of three. You want the foot to reach a little higher than it does in this picture, but it's not easy to position a sock on your foot when it's on needles. I can tell that there's enough extra to get up to the bend of his foot. Between that and your traced outline, you should be fine. (And once you've got knit socks that fit to compare your length to, you don't have to mess with this part anymore! You're going to knit more than one pair, right?)
Come back on October 31 and we'll start working our short-row heel.