Edge sts just means that the first and last k2 sts will form the edge of the whatever you're making. They will always be k2 for the rest of the pattern to give you a clean edge all the way through.
SSK, I can never seem to explain it properly, so if you don't understand what I'm saying, there is a video on the decreases page. It's the first one on the right-hand side.
Ok, so my attempt to explain ssk is: slip the next 2 sts knitwise and do them individually, not together. Then insert your left needle through the front loops of both of these sts and knit them together. They will be knit through the back loops, since your right needle is now only on the back loops.
"Be afraid of bears, of bungee-jumping, of faulty wiring in old houses, but never, ever be afraid of trying something in knitting." Stephanie Pearl-McPhee, Knitting Rules
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