Book selection should be based on:

While two professional selection tools are commonly used, Booklist and Booklink, the former, Booklink, has more of a direct focus on books, libraries and the classroom. All books presented are illustrated - "eye appeal" is an important consideration when assessing how a book might circulate.

Being able to primarily rely one good source is important, it allows books to be reviewed without having to double check and crosscheck from one source to another and eliminates reading lists and recommendations that are constantly referring to the same books.
Each month, Booklink features a different theme.

A subscription to Booklink is probably the best way for a library media specialist to keep abreast of new books and trends in reading. While these types of selection tools are expensive, most library media specialists agree that they pay off in terms of efficiently finding books and monitoring trends. If necessary, another librarian could be located to share access to Booklink (perhaps a friendly public library!)

While Booklink is an appropriate tool to monitor new releases and books as they relate to themes, the The Horn can be another valuable secondary selection tool. Its recommendations and suggestions tend to not be the newest releases. It also identifies books that have won awards, contains essays about books and authors, and suggests things to do to encourage kids to read books. 

The Horn allows the library media specialist to "backtrack" and see what an author has written that is no longer showing up as a new release. It provides an excellent opportunity to see books that might have been missed or overlooked when they were new releases.

While many vendors contact schools and libraries about books, I would tend to shy away from them - building and maintaining a vibrant library media program takes time -- there simply is not enough time to evaluate each and every vendor and all of their wares. 

It is appropriate to consider alternative sources, however, because many books that kids LOVE do not show up in professional selection tools. For example, Junie B. Jones and Bailey School Kids books are not especially noteworthy reads, but children enjoy them, demand them, they circulate.

Web Resources

There are many on-line sources for information about books.  The following are some of my children's literature "favorites" that I keep bookmarked on my computer.