its really easy it just like using your straight needles but instead of having two seperate needles you have one. just knit like you usually do. the big bonus about using circular needles is that you cant lose one of them biggrin . i tried them and i absolutly love them.
you just knit and knit without having to switch kneedles. And you can get St stich without purling. Just try a little swatch with some left over yarn you will probably get it in no time.