This article explains how to use the spell check feature of Google Docs, the online word processor application integrated to Google Drive. Spell checking is available in different languages and is really easy to use.
Open the document. Click on the File Menu > Language and select the language in which the document is drafted from the drop-down list. Now go to the Tools menu > Spelling. Google Docs will check for errors and prompt you to make the necessary corrections. Click on the Change button correct a misspelled word and move to the next suggestion:
It should be noted that the spell check feature of Google Docs is not fail proof and sometimes the proposed corrections won't match to the context of the text. In such cases you can click on Ignore to move to the next suggestion or add the word/term to your dictionary if you intend to use it again in your text.
Click on the x button once you are done with the corrections.