By now, you may have noticed many ways that writing for Wikipedia is different from writing a traditional academic paper. The use of quotations is another difference.
In general, quotations on Wikipedia aren't very helpful. Whenever you're tempted to quote an author, ask yourself: What is my argument for quoting this directly, instead of paraphrasing it?
In some cases, such as writing about a famous speech, political theory, or other article that references a specific text, you may find compelling reasons to introduce a direct quotation.
If you do, be sure to cite it as you would any other source, and to include it within quotation marks.