I normally use Emacs (it has everything you need included).
Of course, there are other options available:
- Kile is KDE's LaTeX editor; it's excellent if you're just learning or if you prefer the integrated environment approach;
- Lyx is a WYSIWYG editor that uses LaTeX as a backend; i.e. you tell it what the text should look like and it generates the corresponding LaTeX
Cheers.
