Google inclusion is by no means automatic. Without knowing anything about your site, here is what Google looks at generally: (caveat, they change the specifics all the time)
1. Use web standards to markup your text. Use h1, p, a, etc. Avoid laying out non-tabular data in tables.
2. Google can't read images. Only use images for headlines if you are doing image replacement.
3. Google can't really read flash.
4. Google usually ignores JavaScript. If you use a lot of AJAX or encase links in it, you have crippled your site in the rankings.
5. Avoid any black hat technique ever used. No white text on a white background, link farms, stuffing keywords into metatags, redirects that intended to show google one page and your visitors another.
6. Pay attention to your page-ranking which, by the way, is affected by all of the above. One client used all images in tables (how 90's) and they didn't come up for the company name. Their page rank was low.
7. Lastly and most importantly, Google counts in-coming links from reliable sites. If no one links to you, you are invisible.