What a fantastic question. Very common too since some of us have had our sites for a long time, before WordPress became popular, or we had our sites built when we didn’t know what options were out there. The answer to this lies in what type of web site you currently have.
If the site is built using static pages e.g. html, Kompozer, Pagebreeze, Dreamweaver, ExpressionWeb etc then you’ll have to manually copy/paste every single page. This is also true if the pages are within a system where you cannot export your pages. For example, you built it using a site builder where you pay a monthly fee to use and they don’t have an export feature.
Even if you can export your content, there’s a good chance the exported content will require some meddling with before they can be imported directly into WordPress. In addition to that, it all depends what format the exported content is in and what kind of information is exported.
Long story short, and the cold hard truth is, it is going to be painful. Speaking from personal experience, I believe it would be beneficial in the long run. Pain or not because having your site in a system like WordPress is so much easier to update. It is also much easier to outsource because you don’t have to trade files with your assistant. Just give them their own login and remove them when you no longer work with each other. Also if you plan to sell a site in the future, a site that is based on a robust publishing engine is going to be more attractive and worth more because people who are buying sure do not want to buy a new software in order to update their pages nor do they want the hassles that come with static web pages.
