I've been doing this for a couple of years now, and made over the 100 mark last year. With that in mind, my goal this is year is 150 books. Something I have learned is that there is no easy way to sort books to make sure they are "fairly" counted. One 600 page book may be half the book that one 200 book is, depending on subject matter. One book will have only 100 words to a page, while the next might have three times that number. My system is based on my overall judgement, and it works like this:
Long works are novels.
Shorter works are novellas and will also include collections of poetry (normal sized one, bigger anthologies would go above) and plays and graphic novels. Their factor will be "3 per book".
Short works will be short stories, essays, individual comics and the like. It will be assumed, partially just for the fun of it, that there are 13 shorter works per book. In those cases where I read an entire collection of short stories, I will list that collection as a whole (and count it by a factor of one). If the collection has 700+ pages, then I will list it as well as a counts as two tag.
The goal is to read enough longer, long, shorter and short works to equal 150 total books by my count.
The total count based on the above formula ended up at 117 + some odd pages. I missed the goal by over 30 books. Dang.