Spell check can't fix everything...

Imagine that spelling is not your favorite thing, so you're relying on the virtues of spell check to keep every word on your manuscript perfectly presented. It'll be great if you spell "coff" instead of "cough" (George Washington always had trouble spelling that word). But what happens when you write a sentence like this:
“Well, Buddy, I hate to do this, but I want to wine so catch me if you can,” Charlie said. When you're proofreading, you might not notice that the word "wine" should be "win." Of course, now your sentence is silly. The way to fix this problem is to have another, experienced set of eyes check your manuscript before you send it off to the publisher. I can wholeheartedly recommend this, because I've been in a similar situation. When my book, Charlie the Horse, was ready for the publisher, I asked my friend, Janice Spina, to proofread it for  me. She found a tiny mistake where a sentence had "you" instead of "your" in it and we were able to correct it. Janice deserves accolades for finding that mistake. As many times as I read and revised it, I completely missed it.
In my book, Charlene the Star, Charlene is a beautiful red horse whose relatives are famous racehorses. But Charlene doesn't like racing so she has her own temper fits to show her displeasure to her trainers. She does little stiff-legged bucks called "crow hops." How horrible would it be if I typed "cow hops" instead! The image of cows hopping around would be amusing, but definitely not the same as Charlene doing crow hops!
As authors, we want our work to be spectacular so we need to use every means at our disposal to accomplish that goal.