My ex's mum taught me to knit, and I learned to crochet from a book - I wouldn't have been able to do it from a book if I didn't already kind of know how to interpret random yarn drawings from knitting. There are tons of videos online these days, though, so that's as good a place as any to start. If the videos don't do it for you, a class is probably good - once you get the basics, you can teach yourself the more advanced stuff. Some people are great at knitting and terrible at crochet, some are the opposite, so if one isn't working out for you, don't be afraid to try the other.