I have just seen an fantastic article on Crochet. It has some of the history of crochet and also many of the different types of crochet and references as to where you can find the instructions on how to do the many variations. I found it because the author used one of my items in her article. It was the Irish Hearts Doily made using the technique of Irish Crochet but with a thicker thread. Here's the link to my item.
This article is very well done and had a lot of thought put into. The author has a booth on Etsy and is also a member of etsyhookers team and the wwwg team. Here's a link to the article:
Here's a link to her shop on Etsy
She has some very interesting items in her shop, but whether you crochet or not her article is very interesting because it displays so many of the different areas of crochet.