Using Permalinks « WordPress Codex: "Creating and editing (.htaccess)
If you do not already have a .htaccess file, create one. If you have shell or ssh access to the server, a simple touch .htaccess command will create the file. If you are using FTP to transfer files, create a file on your local computer, call it 1.htaccess, upload it to the root of your WordPress folder, and then rename it to .htaccess.
You can edit the .htaccess file by FTP, shell, or (possibly) your host's control panel.
The following permalink rewrite code should be included in your .htaccess file (since WordPress 3.0):"
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