This article is important as it refers to a new meta-study that concludes that reps don't matter for strength gains. There are also links to articles from other bloggers like Clarance Bass that are well worth reading.
http://theorytopractice.wordpress.com/2 ... for-speed/
Many resistance training experts claim that a very heavy resistance is required to produce optimal strength gains. However, the size principle, motor unit activation studies, and the overwhelming majority of resistance training studies refute that claim. In fact, these studies support the premise that a moderate amount of resistance will produce similar strength gains.
What matters is the effort you put in.
I think this article is important as many get wrapped around the axle over lifting heavy for strength vs volume. I know I do myself sometimes. The bottom line I take from this is to do what works for you and don't be afraid to experiment.