Can I send a query for my book to more than one agent?
You bet. And if, later, you find out that multiple agents are reading and loving your book, e-mail all of them (separately) and say something like, “Most exciting news to share! You are not the only agent enjoying my manuscript. Let’s set up a call as soon as you’ve finished reading, as I’m in the most unexpected, thrilling position: I get to choose my agent.” Avoid maniacal glee. You get the idea.