Do you want to learn to knit 2 socks at a time on 2 circular needles? Knitting Circles Around Socks: Knit Two at a Time on Circular Needles by Antje Gillingham has detailed instructions with plenty of pictures.
All the steps needed to knit 2 socks at once on 2 circular needles are detailed using a basic stockinette stitch sock pattern in worsted weight yarn. The 14 well-illustrated pages of the basic sock pattern cover every detail of knitting with 2 circular needles to make 2 socks at once.
Once you've learned the basics, there are 8 sock patterns using different types of yarn and featuring your choice of beads, cables, ruffles or lace. These patterns have instructions for a women's small, medium and large sock size. Most of them accomplish this by varying the stitch count for the different sizes. A couple of the patterns vary the needle size to get the different sock sizes. I am not a fan of using larger needles to get larger socks. The feel of the knitted fabric on the bottom of the foot is different and may not be comfortable.
Two of these patterns are basic stockinette stitch socks made in fingering or sport weight yarn instead of worsted weight. These patterns are useful, if you are not experienced in varying the number of stitches to adjust a sock for a different yarn or don't want to bother figuring it out yourself.
The books covers basic sock terminology and measurements and has a table of typical measurements by shoe size. A Knitting Basics section has illustrated instructions for casting on, various decreases, make a stitch, and kitchner stitch or grafting. Adjusting sock size by changing the number of stitches is mentioned, but no details are given. Two pages near the end of the book are devoted to converting patterns from double-pointed to circular needles, which gives you an endless selection of sock patterns to work on circular needles.
This is a excellent book for learning to knit 2 socks on 2 circular needles. All of the basics are covered in detail and once you know the basics, you can knit any sock pattern on 2 circular needles.
6/22/2008 - Addendum: There is a page of corrections for the book at http://www.theknittingnest.com/antjesbook/patterncorrections.html