Useless Ideas About Spelling
Useless Idea 1: The Spellcheck on the Computer will do it all for you.
The simple answer is that it won't. More precisely, it will do a lot for you, but sometimes it won't realise what you are trying to say.
Why are Spellchecks not perfect?
A Spellcheck has no sense of what kind of word might be appropriate in a situation - it just gives you the nearest available collection of letters. For example, it doesn't know if 'spacial' has been written as a mistake for 'special' or for 'spatial'.
Spellchecks are good at catching a lot of common mistakes. They correct 'dessicated' to 'desiccated' and lots of other things. But you can't rely on a Spellcheck to do your spelling for you. It's a help, yes, but don't rely on it.