If you don't even know where to get Arabic characters, but you want to display them, then you're doing something wrong.
Save files containing Arabic characters with encoding UTF-8. A good editor allows you to set the character encoding.
In the HTML page, place the following after <head>
:
<meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
If you're using XHTML:
<meta http-equiv="Content-Type" content="text/html;charset=UTF-8" />
That's it.
An alternative way (without messing with the encoding of a file), is using HTML escape sequences. This website does that jobs for you: http://www.htmlescape.net/