Since text can come from a variety of different sources and different formats, it's difficult to propose one single hardware/software solution for text preparation. Therefore, when preparing text for multimedia applications, the hardware and software identified below should provide a starting point for your own research:
80286 or 80386 based DOS compatible PC (if you plan to re-key the text, you'll need several PCs)
RTF text editor such as Microsoft's Word for Windows
Laser printer to output pages for proofreading
VGA quality display
100 megabyte hard disk
OCR scanner and software
Tools to convert text tagged with word processor or typesetting codes to RTF