ive been reading stitch n bitch n its says to have a size 8 needle for beginners for kniitng, for a worsted yarn, but nothing about a crochet neelde for a dropped stitch. so what size should i have?
Crochet needle
The size of the crochet needle for a dropped st isn’t too important for most things. I would get a size in the middle and that will cover a pretty wide range. The only time I would go smaller would be for very fine knitting, which you won’t be doing in the beginning anyway.
I agree. 
For a worsted weight yarn, I’d suggest a size G hook. It’s not too small to catch that slipped stitch, but it’s not too bulky either. As a crocheter (and knitter of course!), I know that it’s a great all-purpose size.