The English language is challenging. Homonyms and homophones can be tricky. Word processors spellcheck automatically, but they don't all do a great job of checking for syntax errors or ESL translation oddities. You want your content to read smoothly, because the internet is an unforgiving den of Grammar Gestapo, especially if your website has a message board.
I will proof-read and perform minor edits to your essay/presentation/thesis paper/blog post/novel/written work of any kind (up to 500 words) for $5. As an English Major and the Senior Prose Editor of a campus literary magazine, I have years of experience performing this type of work.