What is the best way to determine the correct crank length for my height and more specifically my leg length?
This is probably going to depend on a bit more than just your height or leg length (though I'm sure a rough idea can be gleaned). Your specific bike (geometry) and riding position will also affect crank length a bit.
Here are a few good links on the subject that go beyond my knowledge on the issue.
I disagree with the selected answer as most of the provided links are simply opinion without any analytical backing.
In terms of choosing a crank length on the basis of performance, there is very little scientific support for there being any real discernible differences widely used crank lengths (160-180 mm).
For an overview of some of the scientific results, see this set of PowerPoint slides:
As well, a good summary of the science, in a readable format, is available on the Cervelo website:
Note that in terms of peak power output power output Martin and Spirduso (2001) found no significant difference between crank lengths of 145, 170 and 195mm.
This leaves the choice more as personal preference which may entail a number of details from fit to riding style and comfort.
Other SE questions covering this subject.