The bread experiment 3 (I need help now!)

I am no baker... Yep! I am still not satisfied with my bread. I want those huge and nice bubbles, a nice hard crust, the great taste of fresh bread... I can make a nice crust alright but the bubbles in my bread are small and the taste is just ok. My bread is still far better then the plastic wrapped sliced bread we get at every grocery store in this country but I'm aiming higher.

This time, I put too much yeast and my bread taste, you guessed, yeasty... But even with all that yeast, I didn't get the bubbles I was expecting for. I am starting to think that the secret to a good bread lies with your ingredients rather then the technique... because, believe me, I've tried everything I've read in books and on the internet (except sour dough) and I'm still unable to get what I'm trying to get.

Does bread flour come in different qualities? How much does yeast impart a specific flavour to bread? If yeast is an important factor, what kind of yeast should I use? And how do you get those huge bubbles in a good baguette anyway?