Most amateur writers (and I was one once, too!) think that a quick proofreading is all they need for their work. Not true. Read some of the articles that have really stuck with you in your favorite magazines or reread one of your favorite books. Each word was honed to perfection. Words that were unnecessary were purged from the manuscript. Each piece went through a thorough editing.
Proofreading is very important. It corrects typos, misspellings and punctuation problems. But really, that is all it does unless it is proofing that final galley before publication. Then they’ll also be checking to see if the manuscript reflects the changes that earlier editing indicated.
Ideally, a manuscript should be proofread several times before publication. First, by you, the author. Then by an editor. Then by the acquisitions editor wherever you have submitted your work. Then by an inhouse editor who will further check for problems after it has been edited for length, content, or other criteria the publisher has set in place. It will get another proofing after being laid out for printing.
During this process, your writing is seen by many different sets of critical eyes. Proofreading is just the tip of the iceberg when it comes to editing your work. The more eyes that check it, the better it will be, especially if those eyes know what to look for.
I’ve edited and proofed for people who had their friend, the English teacher down the road, proof their writing. While they may catch a misspelling or two, most English majors don’t spend a lot of time in school learning how to edit. They study literature. They study composition… editing? Not so much. While it is good to get their feedback, it is worth the time and money to hire an editor to go over your work. Proofreading will always be the cheapest route to go. While it will make your writing nicer and easier to read because the spelling and punctuation will be corrected, it doesn’t correct other issues like awkward phrases, inconsistent facts or story points, and other problems connected with most writing.
If all you can afford is proofreading, then by all means get it done. It is still a big improvement. This is critical on websites, too. How can you expect anyone to take you seriously if you have spelling errors or incorrect punctuation?
Sure, you do have a spell checker. Use it. But you also have to understand that it won’t correct words that are incorrectly used while spelled correctly. For example, suppose you use the word “there” when you should have used “their.” Your spell checker may not flag it as a grammatical error. Alternatively, your spell checker could be incorrect. Mine is frequently wrong about words like I used in the example. It often tells me I need to switch “their” to “they’re” or the other way around, when I know which one I need to use. Do you?