what scales are best to weight books on?

why I asked I bought a kitchen scale (at the 99cent store in fact)

will that work?

Any scale will work as long as it weighs things accurately.  I use a kitchen/food scale myself for smaller books, helps determine if FC or MM is the cheaper way to go.

As long as it is digital it should work. I don't think those dial type kitchen ones will be accurate enough. I use my kitchen one I bt at Walmart for smaller stuff, anything over 2 lbs I put on my bathroom scale.

My little food scale is very accurate and it's a dial type.  You can easily test it out with any item sold by weight, put it on your scale and see how accurate it is.  Or, weigh stuff with your scale and then take it to the PO and have them weigh it.  That'll help you determine how accurate your scale is also.