Gabor Filter Mask and Normalization

I have a Gabor Filter, but I need to do two additional things...

1) Filter needs to be 5x5 and x, y vary between -2 and 2. How do I make sure this happens?

2) Components of the filter need to be normalized so mean = 0, and variance = 1. Does this happen after running the gabor filter on an image or before?

If there are any tutorials out there, or any hints you can share, let me know.