It has finally gotten to the point where it's harder for me to hold a dumbbell between my feet than it is to actually do the damn pull up. So, I want to buy a belt. From what I can see, there appears to be just two kinds, leather and nylon.

1) Which is better as far as quality (not breaking) and comfort?

2) I'm looking at them on Amazon. Is there any other recommended place to buy one?

3) Once I get the belt, are there any special tips I should know about before hand? Like how to not bang myself in the nuts with the weights, or just generally not accidentally do something stupid/dangerous.

Thanks in advance guys.