LaTeX for new scholars

In my primary research fields (economics and computer science) most scholars use LaTeX for text processing, as in many other fields. It’s a fabulous tool for those who write scholarly text, especially if the work involves formulas, tables or figures.
It is not a WYSIWYG word processor, but a markup language backed by the world’s best automatic typesetting system (the underlying program, TeX, was written by the god of algorithms, Donald Knuth). On most platforms, however, there are integrator programs that do a nice job of providing an editor, a compiler and a previewer, which on today’s fast machines means that you can see the result of what you’re doing almost instantly. The advantages over word processors (like Word) is that the system is built soundly on scientific principles of typesetting so its default output is gorgeous, and it is infinitely configurable and extensible. (I produce essentially all of my papers in LaTeX; go download one of my recent papers to see an example of how it looks.) And the community of professionals who have written packages and extensions for it is huge and dedicated. The learning curve is a bit steep, though the defaults are so fine that to get up and started on basic term papers, etc., does not take long, especially for anyone with the skills and intelligence of a Ph.D. student.
There are a huge number of guides for starting to learn LaTeX. I still find that my first reference is often the original (though revised) by Leslie Lamport. A widely regarded online guide for learners is Nicola Talbot’s LaTeX for Complete Novices. One you get the basics, the two go-to guides I most often consult are by Mittelbach et al., and The Not So Short Guide to LaTeX 2&epsilon by Oetiker et al.
Nicola Talbot has written (still in process but current draft is available online) a new guide, specifically for Ph.D. students: Using LaTeX to Write a Ph.D. Thesis.