How uniformly is cometary debris distributed along the entire orbit of the comet? Meteor showers occur when Earth passes through debris shed by a comet (if I get that right). Does this mean that the entire orbit of the comet is strewn with debris? I suppose that the debris follows the same orbit as the comet core it was released from as it passed close enough to the Sun for ices of different kinds to sublimate. Is the debris that cause meteor showers somewhat evenly distributed along a huge ellipse crossing the orbits of Earth and (often) Jupiter? 

Are such cometary debris streams, and not only those crossing Earth's orbit, somehow cataloged and characterized?
There are more or less two possibility to get debris in a sufficient amount: collisions and breakup/ejection.

Collisions

This is mostly the case for asteroids. At the point of impact you get a cloud of debris which basically moves as if the colliding bodies combined into a bigger one. However, for small objects, the fragments in the cloud are not gravitationally bound to each other and thus can separate over time. If larger objects survive the initial collision, they can undergo further impacts at different orbital positions leading to the seasonal meteor showers.

Breakup/Ejection

This is mostly the case for comets. Particles get ejected from the original body by heating of the surface, or other effects. This is only possible for small grains, which are massively influenced by stellar radiation pressure. The result is an effectively smaller gravity of the star and thus a different orbit. Being on different orbits, theses particles naturally have to separate.

Conclusion

In both cases you get a physical separation over time. Being that all of the quantities involved are on a continuum, you effectly have a smeared distribution of fragments over an orbit. Depending on the special case, you can get a distribution over the whole ellipse, but a part of it seems more likely.

EDIT: As you asked about catalogues, I would recommend you looking at https://www.ta3.sk/IAUC22DB/MDC2007/ plus at http://adsabs.harvard.edu/abs/2006mspc.book.....J for a scientific read.