Repeat after HMG: Spelling counts.
It does, too. Incorrect spelling makes reading your story more difficult.
It also gives the impression that you don't care enough about your writing
to do the most rudimentary checking. If you don't care about your story,
why should your readers?
Spellcheck. Make corrections. Spellcheck again. Then read the story
to find all those words the spellchecker didn't catch. The spellchecker
doesn't know the difference between "there," "they're,"
and "their," but you do, right? Use a dictionary. When you're
done, have someone beta read for you. Someone who knows at least as
much as you do about spelling. Okay? Good.