If you have a Google Webmaster account and you are in luck.
First make sure your website is added and verified. There are plugins available for common Content Management Systems like WordPress and Drupal to assist with this.
Once you can visit your site via Google Webmaster Tools, click on Crawl and Fetch as Google.
Fetch the website and publish it to the index. Google “should” crawl your site within minutes (not guaranteed though).
When publishing a site to the index, you can choose to submit only the individual page (you can do about 500 of these a month) or have google crawl all the links on the page (you only get about 10 of these a month so use them wisely).