Christmas collectibles is a HUGE area of collecting with many smaller subset areas of collecting. I would think the hard part is deciding exactly and specifically what area of Christmas collecting interests you most. Also deciding what your interest is - is it monetary or memories related? Whatever you decide you are sure to have much competition in any specific area of Christmas collectibles.
My personal opinion is once you have narrowed your area down to a manageable degree, search ebay and see what other people are interested in, search what brings the best monetary return (so you do not collect a bunch of worthless junk), and always keep in mind you must be flexible in whatever you collect as fashion, trends, and collector interest/popularity is a very fluid and rapidly changing thing.
Lastly books are becoming outdated and antiquated due to the vast amount of online information available at your fingertips. I always seem to learn more from online sources rather than from printed material that is rapidly outdated in our fast paced and rapidly changing modern world.
Those are my opinions about Christmas collectibles and collector books in general. And this comes from someone who has "made an appearance" in such books.
