when you start developing game, what steps and precautions should you take to ensure a excellent, fun game?

Well, its important to understand the "doability" of your project, make sure that it's within your skill level to make. Also prototyping your game is a smart idea. Make a small limited demo of your game to test how fun the concept is, if it is, go for it, either you finish the game and get experience or you dont finish the game and learn something, its win-win.

Actually designing a game beforehand is a good idea. It seems like a lot of people start with a seed of a game concept and don't really think the gameplay through. What is the game's setting? What does the player do? What would make this cooler?

sunandshadow (Writing for Games forum moderator) wrote a cool journal entry on that pre-development area. There's a broken link in there that I think might be referring to this page, but who knows.

EDIT: For some reason, I'm unable to directly link to sunandshadow's journal entry, only her journal page. If you follow the link I've provided, and then Ctrl+F the phrase "9/10/2004 9:56:23 PM" that should take you right to it.

thanks for the help, dudes.