An introduction, and the requisite question

Hi everyone,
I'm so glad to be a part of this KAL, it will help tide me over at the office til I can get home and work on my shawl! I am making the large rectangle in spider net and using Louet Sales Kid Mohair in champagne. I just cast on Monday night, but so far its going great and I am loving the yarn. It is literally lighter-than-air. Funny how knitting something that is "barely there" is so incredibly satisfying!
Deciding what would be my first project was a really tough choice. I was leaning strongly toward the half hexagon, but decided against it because I couldn't figure out exactly what the six cast on stitches do. The first row of the pattern is just a YO and a pink square ("do not work at end of RS or beginning of WS row for half hexagon") and I know there are two garter sts required at beg and end of rows - so 1) do the six cast on sts include the four garter sts, or do I have to co 10? and 2) irregardless of the garter sts, what do you do with the other cast on stitches? Are they knitted to bracket the YO of the center section to separate it from the other two? I realize this is probably painfully obvious to many of you but my brain can't quite get around it. Your help is much appreciated.
I will post photos of my spider net soon - I just moved and can't exactly locate my camera. But somehow, I managed to easily find VLT, the yarn, and my needles!