Hey, I'm in the process of up dating all my pages from html to shtml so that I can use includes. How will changing the page from html to shtml affect my google rankings?
You need to use 301 permanent redirect to tell search engines that the html files and now changed to shtml. web-page.html and web-page.shtml are not the same page in the eyes of search engines. If you change from web-page.html to web-page.shtml without properly informing search engines, your may lose your credibility from the old pages and have the regain the credibility in the new pages, which can take a long time. Changing the file names can affect your Google rankings. You need to proceed with caution and make sure you do everything you can to minimize it.
You could always setup apache on the server to treat html files as shtml if you have access to the server to do this, depends on how your hosting the site really. Alternativly you will have to just do 301 redirects as already mentioned. htaccess file way Enabling SSI If you want to use SSI, but can't do so with your current Web host, you can change that with .htaccess file. The following lines tell the server that any file named .shtml should be parsed for server side commands... AddType text/html .shtml AddHandler server-parsed .shtml Options Indexes FollowSymLinks Includes If you don't care about the performance hit of having all .html files parsed for SSI, change the second line to... AddHandler server-parsed .shtml .html If you're going to keep SSI pages with the extension of .shtml, and you want to use SSI on your index pages, you need to add the following line to your .htaccess file... DirectoryIndex index.shtml index.html This allows a page named index.shtml to be your default page, and if that isn't found, index.html is loaded. Source: http://www.buildwebsite4u.com/advanced/htaccess-file.shtml