Start by casting on the required number of stitches, onto one of the double-point needles. Divide these stitches between three needles by slipping 1/3 of the stitches (beginning with the first stitch you cast on) onto each of the other two needles. Making sure the stitches are not twisted on or between the needles, form a triangle with the three needles, with the opening at the top. There are many ways to join the stitches "into a round," but this is the one I like best. With the tip of the right-hand needle, slip one stitch from the left-hand needle to the right. Then, with the tip of the left-hand needle, reach over the stitch you just slipped, picking up the next stitch. Lift this stitch over the first stitch and leave it on the left-hand needle. Now you are ready to begin knitting with the fourth needle.
PartII (Click on Chapter 2)
With the working yarn at the point of the triangle facing toward you, the needle positions are numbered - needle 1, 2, and 3, moving clockwise around the triangle.You begin by working all the stitches on needle 1, onto the free needle. You now have a new free needle and proceed to needle 2, always knitting around clockwise, with the working yarn at the front point and the right side of the fabric facing out. One trick to this is to ignore the two dormant needles. Just let them hang there while you work with the two active needles.
Part III (Click on Chapter 3)
The Part III video discusses a common problem faced by knitters new to double-point knitting. When you are getting started knitting with double-point needles, it can be difficult to keep the tension even when moving from one needle to the next. It's not uncommon for gaps to form in the knitting between the needles. This is referred to as laddering. To avoid these gaps, I knit the first stitch on each needle as snugly as possible, but the real trick is in beginning the second stitch. Put the tip of the right-hand needle into the next stitch. Now give an extra tug.