Join into a Round
What does it mean join into around when making a hat?
I am assuming that you are knitting your hat on double pointed needles or a circular needle and that the instructions are telling you to join into a round (rather than join into around - subtle difference but an important one).
Basically this means that you slide the last stitch of the previous row to the tip of the right hand needle and slide the first stitch of the same row to the tip of the left hand needle.
Then you join your knitted piece into a circular piece of knitting.
There are a couple of ways of doing that depending on how you want your edge to look like.
The first way to join your knitting is to just start knitting the next row. I tend to do this when I am starting to 'knit in the round' at some point after the cast on edge rather than on the cast on row.
The second way is better for joining the cast on row. Here is what to do:
Slip the first stitch on the left hand needle onto the right hand needle. Using the tip of the left hand needle lift the second stitch on the right hand needle (the last stitch you cast on) up and over the stitch you just transferred and slip it onto the left hand needle.
When knitting the first stitch on the left hand needle I usually knit into the back of the stitch. You only need to do this once, at this point you should have a continuous circle of stitches on your needles.
© Kirsten Skiles | Flickr - Knitting a Hat in the Round