To help you edit a document for spelling, do NOT trust spell-checker. I told our fourth-grade daughter the same some years back when she was preparing a paper on the Yaqui Indian Nation. An aquaculture, they catch lots of fish. Her paper ended up saying they most enjoyed eating "white surgeons."
Spell-checker missed the irony, of course, and she would've submitted the cannibalistic sentence were it not for Daddy's vigilant proofread.
To avoid the same pitfall, it is very useful to check for spelling by going backwards through your document from end to beginning. Avoid reading the sentences in reverse order: literally read the document backwards word-by-word.
This helps you avoid reading quickly through sentences you've written yourself and accidentally skipping over speling misteaks. (Ha ha!)