Markdown is a popular and easy-to-use markup syntax. This tutorial and a free script help you go from marked-up plain text to styled in seconds
Download the script and support docs from here:
https://luminousworks.com/resources#markdown
Lots of other tips and resources there too.
UPDATE: The script has been updated and now formats tables, converts items like "(c)" to the proper glyph ("©"). It also prompts the user to load styles from an InDesign doc (included) so you don't have to remember to do that. In addition, you could always edit the styles in that doc so the converted content matches your preferred look and feel as soon as the script is run.
The download also includes an instructional PDF with some background info.
I will make a new video tip soon-ish, but this one still does a fair job of describing Markdown and how awesome InDesign's Find/Change feature is.
