The 'wrong side' is the side that is, say the inside of the sweater, or the back of a blanket. The 'right side' is the side where the pattern shows, like the cables or color patterns.
For stockinette stitch, the wrong side would be the side that gets purled.
If a pattern says start with wrong side--its just to inform you that this next row is the 'wrong' or 'back' side. It helps you to keep track where you are.
"Trust the pattern!"
Time flies like an arrow, but fruit flies like a banana.
Hop aboard while we follow the cloud-covered van of knitting harmony, man!! Woooo!! --Hedgehog
IngridKH on Ravelry