All characters can be artisans. It's not a seperate class.
The recipe books are sold by the merchant in the tradeskill instance. Not the one behind the desk. If you're good, it's the merchant downstairs. And if you're evil, it's the merchant upstairs.
Once you buy and scribe a new recipe book, you'll get new recipes. But only buy the book that corrosponds to your level. If you're a level 3 artisan, buy the level 3 book, and when you get to level 4, you'll get the level 4 book, and so on (sorry if that was obvious, lol)
Also, make sure you have the right components. Also, sorry if this is obvious, but you were a bit vague in your post.