If you have a website, then you most probably want google to index your sites content.
the easiest way to do this is to submit a sitemap to google, using webmastertools.

1) Make sure you have a sitemap
If you run wordpress then there are plenty of plugins that will generate a sitemap.xml file for you.
there are also plenty of sites out there that will crawl your website and make a sitemap manually for you.

2) Create a google webmastertools account if you don’t already have one.
Once you have created the webmastertools account and have verified it, you will then need to submit your sitemap:

To submit a new sitemap, go to your sites dashboard in webmastertools, then click on sitemaps
or goto Crawl > sitemaps in the left menu

Click the red ‘Add / Test’ button and fill in the url to your sitemap.

Google will now process the sitemap in its own time, and pages will be added to googles crawler.