Markdown is a language that is supposed to make writing easier by letting users compose formatted content in a plain-text editor. Getting used to some of the syntax can take time, but there is a lot of intuitiveness behind it as well. Once you decide that you want to give Markdown a try I recommend checking out the free MarkdownPad app for Windows.
What’s nice about this app is that it provides a live preview of what you’re writing, which can be extremely useful if you’re just starting to learn the syntax. The appearance of the live preview is also customizable (even through CSS) helping you exactly match the appearance of where your text will be posted.
One of the other nice features is that once you’ve written your text you can copy a portion as HTML, or you can export the entire document as HTML. That feature is pretty important because it means you can take your content to just about any web platform.
MarkdownPad Homepage (Windows only; Freeware)