How to sync iPhone to new iTunes without deleting my books?

I have a new iTunes on my laptop (PC) and I want to sync my iphone 4S but when I click sync or apply it tells me that I could lose the data. Please if someone could tell me how to sync it without erasing the books from iBooks. I don't really care about the apps but the books are very important to me so I don't wanna lose them.

Will 16 gb be enough for iPhone 6? - 1

I'll be getting a 6 for Christmas. I'm planning on having about 50-100 songs, about 400- 600 pictures, some videos (I'll offload the lengthy ones onto my PC), some 15- 30 apps, and about 6- 8 games. Maybe 1 or 2 of the games a high graphic one. I think this should be enough, but I just want to know if you think it is.

My iPhone 4s camera is frozen?

I tryed to take a selfie and the screen just stayed on a black image! I can flip to different things on the camera thing like the square camera options and others but it stays on a black image and I can't take a picture from the back or the front! I'm so

IPhone 4s using a lot of storage?

My iPhone 4s can hold up to 5gb of storage and I'm currently using 3.1gb I have only one or two apps with over 200mb and the other 13 are under 70, i have deleted all my apps before and somehow with the default apps there was still 1gb worth of storage being used