nonferrous electromagnets

Hi all. Been thinking about a project involving nonferrous 
electromagnets, attracting metal with low electrical resistance like 
copper, alluminum, gold etc... Want to know if anyone here knows 
anything or has any experience with this subject. I have searched 
the archives and found no mention and what I did find did not 
understand much. I have a book on order about how to make one, 
just being impatient and thought someone might know from 
experience. Thanks for your time, Mark