Google is the worlds largest search engine for queries. It gets over 30 billion search requests per month, so it makes sense to optimize your site to rank better in Google. Thankfully, Google has a couple nice tools that provide you with some insight on how your website performs on the Internet. These tools are completely free, but don't let the price fool you, they are commercial grade!*
Google Webmaster Tools (GWT) for short allows you to submit sitemaps for Google to process and crawl. There is a lot of confusion about what a sitemap does, and I'll settle that for you once and for all. The sitemaps main purpose is to increase crawling efficiency by providing information to spiders about web pages contained in your site. Sitemaps give the most benefit to sites who's web pages may not be directly accessible via a web browsable interface (no links to them). The sitemap only SUGGESTS URLs to get crawled and indexed in the search engine, it does not guarantee a page will be indexed. *It also does not influence the ranking of a page.
Many available softwares today have either a built in sitemap feature, or one readily available through modifications. I highly suggest everyone who runs an online community to always use a sitemap. Due to the nature of forums, and that most are poorly designed and linked, spiders can easily get confused and crawl unnecessarily eating up your bandwidth. Once you've got your sitemap up and running the first thing to do is verify your site ownership in GWT, and submit the sitemap.
Once you've submitted the sitemap, check back in 24 hours to give Google time to read and process the information. After about 48 hours some statistics will start to become available in GWT. You'll be able to see if your sitemap is valid or contains errors. The main keywords that appear the most in the sitemap, incoming links to your site, crawl errors (403, 404, 503 type errors). Validate your robots.txt file, and more.
Using Google Webmaster Tools can provide any webmaster a great deal of information to better optimize their sites. It's free so why aren't you using it? If you are using it we'd love to hear how it's helped you grow your site, and if you have any tips and tricks to share with fellow webmasters would be wonderful!