All my posts have multiple links since there are multiple categories on them. For example: http://wegotthiscovered.com/news/tomb-raider-pree3-cinematic-trailer/ http://wegotthiscovered.com/PS3/tomb-raider-pree3-cinematic-trailer/ It's filed under both the news and PS3 news categories so it shows up at 2 links. Is this bad for SEO purposes? On a related note, how can I tell if I am using canonical URLs?
If the same page shows up with 2 different URLs then that is bad since Google would view them as different pages with duplicate content. If you want to continue to use both of them, then you should setup a canonical meta tag pointing to the one you want to receive credit in the search engines. To determine if you are using a canonical tag look in the source code for the page and see if there is a tag similar to this '<link rel="canonical" href="http://www.example.com/product.php" />'. If you see this 'link rel' tag in your page then you are using the canonical tag. The URL listed in the href attribute (http://www.example.com/product.php - in this example) is the URL that the search engines will credit for this page. If you do not see this code in your source code then you should add it. Below is a link from Google with instructions on how to implement it. http://googlewebmastercentral.blogspot.com/2009/02/specify-your-canonical.html
For the example pages you listed above, both of them have a canonical tag and they both are pointing to the same page so you are good. You should not have any duplicate content issues. Same Canonical Tag on both pages: <link rel="canonical" href="http://wegotthiscovered.com/news/tomb-raider-pree3-cinematic-trailer/" /> For this article the 'http://wegotthiscovered.com/news/tomb-raider-pree3-cinematic-trailer/' URL will be the one the search engines credit.