Think of LaTeX as the nerdiest word processor you'll ever see.
LaTeX focuses on content, and does all the formatting for you (kind-of). The end result is beautifuly typset documents based on style sheets with auto labeled equations, figures, and tables.
I love using LaTeX in conjunction with BibTeX to automatically format my citations and build my bibliography based on the citations I've used in my documents. Mendeley will automatically build your .bib files so using citation keys is easy, just click on Preferences->BibTeX and check "Enable BibTeX syncing."
To get started download an appropriate LaTeX package here. Once it's installed, start by searching for a template for what you would like to work with. This could range from a journal article (many times, professional journals will have their own template on their webpage), a report, a book, or even presentation slides.
When entering content, there can be a bit of a learning curve. I've found this LaTeX Wikibook extremely helpful, as well as this blog. The learning curve is steep, but the end result always looks awesome. So awesome in fact, i heard a story about a guy who got a highered simply because he made his resume in LaTeX!
Does anybody else have any helpful latex tips or resources?