So, please, Teachers and School Librarians, if you are assigning a project to write to me (or to any author) or assisting students in figuring out how to contact me, do not tell your students to use the publisher's address. I'm not sure why, but it seems to take publishers a very long time to forward it to their authors. Of course, it also seems to take many of them a long time to answer their authors' questions and other correspondence as well, but we know the drill by now. Students can't be expected to know they'll have to wait so long.
First, have your students check the author's web page. I have my snailmail address on my home page and a link to my e-mail address on every page. Most writers have contact information - if not their home address, their agent's address. Agents are much speedier than publishers about getting any correspondence to their clients.
If you can't find any contact information on the author's web page, try Googling the author's name plus the residence information shown on the book's flap or the "About the Author" section in the book. Yes, we move over time, but that's a start. A little time spent Google-searching can save months of time waiting for a reply.
Unless you're combining author research with teaching letter-writing skills, urge your students to e-mail for the fastest possible reply. I must admit that I've received e-mails stating that the student has a project due tomorrow morning and can I summarize the plot of my book, identify the climax, describe the characters, identify the theme, etc. for him or her? And I answer these also, although I confess I tell those students that I cannot do their project for them, but they have to read the book. Even with legitimate personal questions such as how I came to write that particular book, or why I had this character do that, it's better to e-mail earlier than the night before the book report or paper or project is due, in case I'm out of town and unable to check my e-mail.
Here's the thing about corresponding with authors: we do not want to disappoint our readers - ever. Please, please help us keep your students happy and satisfied by making it easy for us to answer them speedily.