These are two quotes from John Scalzi. They're paraphrased here, because I don't feel like looking them up word for word now.
"The Writer's Market has about 4,000+ listings for agents, publishers, and magazines so you stand a reasonably good chance that someone out there wants to publish your stuff if you write at a decent level."
-Sometime in 2004
"You can expect a 98% rejection rate, on a good day."
-One of his more famous writing advice entries, check the Best Ofs