Better ranking in Google search results means more visitors to your website which means more revenue.
here are some tips for getting higher ranking in Google:

1-Inbound Links:
Google ranks your page according to the number and quality of pages linking to your page.
so a page with 100 quality inbound links will rank higher than a page with 20 inbound links.
Note that Google looks only for links that is relative to your keywords.
for example if your website is about Search Engine Optimization then a link from a page about Cell phones will not help your ranking .
Always try to get links from relative pages.

2-Title Tag:
Search Engine gives weight to the title of your page, try always to include your keyword or key phrase in the title of the page.

3-Keyword Density:
Search Engines love Text, they do not understand images or video and flash files.
Keyword density in your page's test is a large factor in ranking your page.
Some people said that it should be 10 % but to be safe and to avoid Keyword stuffing it should be around 8 %.
Note that sticking your keyword everywhere in your page and going beyond the 8 % of the whole text will be considered Keyword Stuffing which will harm your ranking.

4-ALT Tag:
If you have to put images on your page then you should add ALT tag to them Google read those tags in index them.

5-Keyword META Tag:
Many people said that it is ignored by Google, but many other search engines like Yahoo still use them, so i think that you still have to use them but make sure that every keyword listed in the meta tag appears at least one time in the body of the page.

6-Description META Tag:
A good meta description give the user a clear idea about the contents of the page, so you should provide a unique meta description for every page, and do not duplicate the text already in the Title tag.
In the main page put a description for the whole site and for every single page put a description for the contents of this single page.

7-Sitemap:
you have to submit a sitemap to help search engine find your pages and index them.
there are many free tools on the web that create a sitemap for you or you can do it yourself using any text editor.

8-Content is the King:
All what we said before in this page have nothing to do to your ranking if your content is poor.
your content must be unique.

9-Update Daily:
Search engines like the fresh content, try to update your content daily or at least every three days and you will notice a great difference in your ranking.