Are my margins set up wrong?

[GerardA1969]

My book that I'm designing is 7.5x9.5 inches. When I output a PDF the pages look fine. But when I print draft copies of the left and right facing pages, a small narrow band from top to bottom from the right facing page (left portion) is printing together with the left facing page (to the right of it). Hope this makes sense. Not sure what I need to adjust to print them out so I don't get a portion of one page (right) showing up on the left page design. Help please!

[Derek Cross]

You would normally supply your printer with single pages, not spreads, ready for them to impose.

Tick Crop Marks and Use Document Bleed Settings.

[GerardA1969]

This issue only happens when I'm printing back to back single pages on my home printer as draft pages. This is when this issue happens.

[Scott Falkner]

Don’t expect a home printer to perfectly align the front and back pages of a double sided document. This is not a good simulation of how the print shop will handle your file. If you really need a simulation of how the pages will print double sided, print single sided with crop marks, use spray adhesive to put them back to back using the crop marks as a guide (a light table or an iPad will help with this), then trim. 

[rob day · Accepted solution]

But when I print draft copies of the left and right facing pages, a small narrow band from top to bottom from the right facing page (left portion) is printing together with the left facing page (to the right of it). Hope this makes sense.

That would be the inside bleed, which comes from the opposite page in the spread when you include an inside bleed with a facing page document.

Unless the binding is an unusual method like wire-o where the inside edge is trimmed and visible, you don’t need an inside bleed and can set it to 0. If you do include an inside bleed it will be removed by the printer when the document is imposed.