Pwaring is right. Most important is content. (and the t-shirts on beautiful girls could help too)

Other things you can do:

Have clean code using css. Use tags as h1, h2... Do not use table design - google and other search engines likes sites where they can find big ratio of text. Much better is something like <div id='content'>content... than <table><tr><td><tr><td><tr><td>content...

btw. You can get your content size using this favlet:
Code:
javascript:void(open('http://www.holovaty.com/tools/getcontentsize/?url='+escape(document.location)))
(without that space in javascript)

Use mod_rewrite to have nice urls. Much better is url like something.com/this-is-nice-url than something.com?id=25478asd895. But I don't think, you can do this at .tk domain.

Get links to you site. Google pays big attention to how much your page is linked. Good back link can help very much.

And! Have good readable content.