I'm a beginner and I need some sock help!!!

I've been wanting to try socks for quite a while now and have decided to jump in and go for it. I am knitting from the sock book 'Knit Socks' by Betsy Lee McCarthy and I'm doing the first sock pattern using only one color. That's another fear I have to conquer

I am now supposed to start the heel flap and I'm not at all sure how to do it. I've looked online for good picture descriptions but haven't found any so far.

I'm confused about the 'turn work' part. Does that mean I have to turn the sock inside out? Am I overthinking this one little sentence?

Plus I have this line down the sock, its the starting point I guess you would call it that I change from k to p. And what's this business of r side, w side?

And one more thing, in the 'Turning the Heel' section the first instruction is written like this: Row 1 (ws): Slip 1, P____, P2tog, P1 turn back to rs.

WHAT THE HECK DOES THAT MEAN??? What's with the underscore???

HELP MEEEEEEE, Please.

TIA.

[misstialouise]

when you knit the heel flap, you'll only be knitting half the stitches along the back. Which is why you need to turn the work.

As for the underscore, I'm presuming it's a 'calculate y