This question has many answers, depending on how much time and money you’ve got to devote to the project. If you want to do it right, get a decent scanner and some OCR (optical character recognition) software, such as Readiris Pro ($129.99), to digitize the docs and convert the text from a graphical chunk to actual words that you can edit - and more importantly, that a search engine can read. Scan the pages at 600 dpi and follow the OCR software’s instructions. The hard part is dealing with the monotony: Scanning, OCR-ing, and proofreading those 5,000 pages will make a slow day of fishing seem like an extreme sport.
And getting them online is another kettle of fish. You could set up an actual database-driven system, such as the free blog kit Movable Type and enter each article as a post. Or you can set the OCR software to export Web-ready HTML files, which you can incorporate into your existing website and easily add a Google search engine (free). Plan B: Save a little time up front by scanning the files straight to PDF - then give the time back while tagging the files with searchable keywords.
Adding Google Search to your website is the easy part.
