I agree with the others that I don't think slipping the first stitch will keep your edge from curling.
There are a lot of combinations of stitch treatments to acheive that slipped stitch thing. One I like is to always knit the last stitch in a row no matter what stitch you are using. And then with the yarn in front, slip the first stitch as if to purl, no matter what you are doing on this row. I pull on the working yarn as I am slipping that stitch, and again as I begin to work the first actually worked stitch in the row. I get a pretty good result with this.