I never use it at the end of a sentence. It is mostly used as an adverb, but is also an adjective. I would say 'I seldom read a book that I dislike' or 'Seldom do I read a book that I actually dislike' It is a seldom occurrence to see it at the end of a sentence. But you could say 'I seldom read' or 'I read seldom' if you wanted to.

You can use seldom at the end of a sentence often or you can use it seldom.