Virtually all software development happens inside a text editor. Picking one that you like and can become proficient with is very important.
Some text editors to consider:
Challenge your text editor fu — October 17, 2011
Challenges that encourage you to master your text editor
Write HTML/XML faster with Zen Coding — October 20, 2011
Making your text editor write more HTML for you
Don't be affraid to learn vi or emacs — November 23, 2011
How to go about learning hardcore text editors