I have a couple questions about using a content manager on an existing website. 1. If I convert my website to a site managed with a content manager (php, MySQL) won't all the pages be re-named with .php extension from html? 2. Because of that won't I lose all my links and Google Page Rank to those pages?
1. Yes, it will be .php 2. You wont, depends on how you put back your links to .php files, you wont lose your pagerank because of that, I change mine frequently to test all the system, and my pagerank still the same, if you need some professional service to migrate them, you can PM me.
Actually, no it won't, IF you pick a CMS that supports SEO URL's. I am a big fan of Joomla, so I am admittedly biased. Basically, using Mod Rewrite, SEO components for Joomla and Mambo (not the built in ones) take what would be a dynamic URL such as http://www.yourdomain.com/index.php?some_query_String and turn it into something meaningful like: http://www.yourdomain.com/any-darn-page_name_you_choose.html If you through in a Meta Tag manager component, you should be able to not only maintain position (provided you know how you got it to begin with) but may well do better than before. That has been my experience anyway, but to be truthful I am fully aware of how I got my rankings, so replicating these techniques on my Joomla site was a breeze... Your bigger concern, IMHO, should be the learning curve needed to master a CMS based on your current abilities. Remember that "easy to use" in no way means "easy to install"