Good questions. There is (as usual) not always a "right" way because there are a lot of factors to consider in the content of an individual site. It the opinion of many, including myself, that shorter, "chunked" information works better for the purpose of usability and readability on the web. And of course, by dividing up the content by topic you can optimize pages to specific SEO. As to your last question, I can think of no good reason to break up a long article across multiple pages except that its long and someone felt that was necessary. Truly though, that would be the one time I'd probably just opt for a longer page!
My views on usability and hypertext design don't necessarily jive with
all perspectives - for example, the standard sales letter is usually many screens longer than anything I'd ever come up with. But from what I've been told there is a whole art behind copy editing those long sales letters, so I accept it as an exception!
Along with my tendency for pages that are no longer than one "page" (a screen full, roughly the same as one page of MS Word), when I develop sites, I try to provide multiple navigations and multiple ways that someone can access the information. A standard top level navigation and sublevel navigation to break up the sections of the site, of course. And usually a site map for people who want to browse all of the available sections - if its a large site, I tend to go three layers deep and no more. If it makes sense, search functionality for people who want to really target specific terms. I also do a fair amount of cross linking - one page or topic available from multiple directions, as relevant. Kim's observation is a good one also - scrolling is difficult for many people. I have "mouse shoulder" - after so many years of mousing around and a bad rotator cuff tear a few years ago, it pains me to scroll. So, I have a wheel mouse and that helps, but still, the more clicking I can do with the flick of a wrist to move around, the better.
Hope this helps a little - one web designer's opinion
Eileen 'Turtle' Parzek