Let's say I wanted to gain expertise in a certain area of children's/YA lit.  Say, I don't know, modern books about the ancient world - especially Greece and Rome.  Mythology and history both.  How would I go about staying abreast of new releases that would fall into my area of expertise?  Catalogs?  Reviews in the Horn Book?  Something else?  All suggestions are welcome!  Also suggestions of older books that fall into this domain are GREATLY appreciated.  (Already know Percy Jackson etc, plus Nobody's Princess and related books.  Oh, and Iris, Messenger.)