How long will it take for my hair to get long natural curls?

I have natural hair, but have been getting it straightened professionally most of my life. I tried to go natural for one weekend, but I wasn't happy with the results because I didn't wait it see what it would look like with progress. Since it's summer now, I don't have to worry about it being straight for school or anything, so I was thinking about trying for the natural look again. I have two questions about it though. How long will it take for my hair to get its natural curly nice look? And will my curls be long loose curls or tight tiny curls? I use Mixed Chicks and I have hair long enough to reach my mid back, so its pretty long. If they are tiny tight curls, how can I make sure they become long loose curls?