Currently reading 'Day of the Tempest,' after just having finished 'Dawning of a New Age," and I bet y'all can't guess what I plan to read next! Go on! Guess!
I'd say it takes me about 2 weeks to read an average-sized book (Like 300-400 pages). Any longer than that takes longer, any shorter takes less. Also, how good the book is plays a factor. I think the fastest I ever read anything was a 300 page Terry Pratchett book in 2 days.