I do go to Noho all the time, but I don't go to that store anymore, because I don't think they like me.
I think they thought I was a show-off with all my obscure technical questions while researching this site. I think they're a great store, and I always thought they were nice people; it broke my heart when they started acting coldly to me. I should probably try to work it out with them, but I'm afraid I'll get all emotional and just make a fool out of myself. (There's my little local saga for you!
From the sounds
of it, I'm wondering if the cast-on the pattern called for (or meant to call for) was a "provisional" cast-on of some sort: one you can easily undo to expose live stitches. This would explain why you need to slip existing live stitches onto the needle. This would make a nice, invisible seam around the waist, and would make a lot of sense to use. If you're already this far along, and not at the cast-on point, you can do one of two things:
--Undo the cast-on edge, just picking it apart the hard way, to expose live stitches. May be a bit tricky, but definitely possible. Or you can just cut the strand of the row adjacent to the cast-on, and pull out that strand, exposing the stitches.
--If you don't mind a visible seam at this point, you can indeed just pick up stitches. You probably want to pick up stitches all the way around, and then work from there. (I assume you'll eventually be working the other side, and will need live stitches on that side as well.)
To avoid holes, you can use the "short row with wrap" technique in the advanced technique section.
If you're still confused about the pattern, you should call Northampton Wools and ask! They really do know their stuff there, and if they sold you the pattern, they can certainly help you with it. And I'm sure they'll be nice to you! (If you don't tell them who sent you! LOL!)
Let us know how it goes!