How can I achieve this? I want it so when a page loads, it automatically moves the mouse to a specific div or area on the website.
Aaah, no, but its not hard, especially if your site already has jquery loaded. Depends on what you want the focus to be, normally an input field. What did you want the focus to be? The other alternative (just in case I'm overthinking this) is that you simply have <a name='jumpspot'></a> Code (markup): and then your link is page.html#jumpspot
This would be a sales page, so if a user were to come to this page. The mouse should automatically hover over the button, or buy now link I have, as soon as the page loads.
If I understand your question, you want to move the actual mouse pointer to a specific spot/element? If so, that is not possible in Javascript, not even with HTML5. The only thing you can do with Javascript is to set focus to elements, move the selection cursor to a specific spot or actually select text.
And it would piss me right off! I don't mind if it was, say, help text showing me where something is, but a buy button? Would seem pushy or desperate. Look for a more user friendly way of encouraging sales.