Before I start listing and throwing down some knowledge of known pedigrees, I thought I'd try and explain what they are first. A pedigree is a collection of comic books from the Golden and Silver Age. There are certain criteria that a collection must meet in order to be considered a pedigree. The criteria are as follows.
1) The collection must have been bought by one person off of the newsstand as they were released. Only comics bought in the 60's or earlier are eligible to become a pedigree collection some day. This means that you or I can't buy older, ungraded books from your local comic shop, at a convention or online and then 50 years from now the collection will become a pedigree. It doesn't work like that and that time has already come and gone, unless you hop into your Delorean and travel back to 1955 with Marty McFly. If you do, remember to bring extra plutonium.
3) The collection must be more than a few comics. It has to consist of a considerable amount of books. There are some collections that have only one or two hundred books, but there are also collections with over 10,000. If the collection is a smaller one, then most of the comics in the collection have to have significant key issues in them, or be extremely rare.
4) The fourth and final requirement of a pedigree comic collection is that they must all be in high grade. This is pretty self explanatory. Like I mentioned before, a Silver Age collection must be of very high grade averaging a 9.4 or more. A Golden Age book is a little different. These books have to be high grade or the highest grade of those that are graded. For example, if your Golden Age key issue is only an 8.5, but all other known copies are only a 7.5 or 8.0, then that comic could be considered for the pedigree.
Well, If I did my job right and wrote clearly enough, then this should help you understand pedigree comics a little bit more. If I didn't, then you're probably just as confused as you were before, but I hope it helps you out.