I had some experience with growing too fast in my first start up. It was painful, luckily we made it through.
I see growing too fast as both one of the greatest temptations and killers of start up companies. As an entrepreneur my first instinct is always to say yes we can do that work, and thanks for the check. Unfortunately, growth is not always the best choice.
Tim Ferriss has a good article on start up growth, as well as some other useful insights: http://www.fourhourworkweek.com/blog/2010/03/08/why-grow-and-other-wisdom-from-37signals/