Guides to using words, phrases and grammar for writers and editors.
Style guides are used by writers to keep up with changes to the language. Also for improving their own use of the language (words, phrases and grammar) in their writing. Often newspapers put out a style guide for their writers and editors.
Automated spelling resources can be a great help, but should not be relied on to be the final authority.
"I have a spelling checker,
It came with my PC;
It plainly marks four my revue
Mistakes I cannot sea.
I've run this poem threw it,
I'm sure your please two no,
It's letter perfect in its weigh,
My checker tolled me sew."