Once you have researched and decided upon your keywords you need to consider using the right keyword density in order to achieve the best possible results from your SEO.
Getting the balance between good keyword density and well written content can be a fine line, ultimately you should focus on well written content for you website with around 2-3% keyword density.
Having your keywords placed within your websites content is very important as it tells both the website visitor and search engine what your website is about. When a search engine has a clear understanding of what your website is about it will be able to rank it accordingly.
When creating homepage content your first focus should be the web user, there is no point having a website on page 1 of Google if all the visitors are put off with poor on page content.