Galleys is a standard industry term for advance copies that are bound but unproofed, and often will go through one more round of edits. WVU author, your publisher should have a complete press kit that could include a general release, book information, an about the author page, some interesting facts that can be used as a sidear for a drop-in article, and, ideally, a prepared Q&A the publication can use to simply drop in quotes and do a story without having to actually interview the author. If your publisher isn't interested in doing this, then do those things yourself and include the press kit with the review copy.
The cover letter can say what Jenna suggests, but I would suggest taking the "i'm an author from XX," going with a much more general letter like, "Dear Book Review editor,
Per your review requirements, here is a galley copy of Title of Fabulous Book, by Soon to Be Famous AUthor.
A two-sentence description of what someone might find in the book (ex: From reed boats, papyrus, and amulets to pyramids, pharaohs, and mummies, Book Title explores the fascinating lives of ancient Egyptians with 30 hands-on building projects for kids ages 9 and older. Please find the book information below:
Author: Your Name
ISBN: 0222222222
Size: 8 x 10
Pages: 128, one-color
Price: $14.95
Pub date: November 2006
That's all you need, with contact information and a line that says, "More more information, contact XX at XX."