The Most obvious Choice would be Desktop Publishing (DTP) Software, that is what print professionals tend to use for such tasks. Programs like Adobe InDesign, QuarkXPress and Microsoft Publisher focus on the task of grouping the text on the page, drawing boxes around it, and on the general typography. Joe Internet has linked the most important ones already.
There is one more worth noting, and that is TeX. TeX (or one of it's popular derivatives/extensions, like LaTeX) produce professional output on par with the commercial DTP packages, but are completely free and open sourced. The trade of is that they aren't using a visual composition method, using them is more like programming, or writing HTML, though there are graphical editors available. There is no one TeX site, just Google for LaTeX.
Office Word Processors (Word, Open Office) and Graphics Software (Photoshop, Corel Draw, Illustrator, The Gimp) work too, though you won't have as much control over typography. Advantage of Word Processors is that most people have one installed already, and with Graphics software the advatage is better control over the graphical side of the product (diagrams, images and such).
The bottom line is there is no one choice for this task, experiment and use what works best for you.
Linkify, FF-AddOn. – Bobby Jul 7 '10 at 10:41