Q :How many cross stitch books do you own and how often do you use them?
A : Well this question could be interpreted two ways, I wish it was a little clearer. I interpret the question as how many stitching reference books do you have and how often do you use them? I have less than ten and I use them very rarely. I find often the answer can be faster to find on the internet, or I know exactly where to go. For example when I need a stitch diagram I check at Victoria Sampler's VS Club. There they have provided animated stitch diagrams which are just fantastic.
Another way to interpret this question would be how many charts do I have? Too many to count!