o.fithcheallaigh:
From tests I have done, the relationship seems to be linear, yes. As for the resolution, yea, I think 1 gram would be good, but they may settle for 10 gram steps.
In that case, find the minimum weight that gives an analog reading of 1024 and use map to get the weight. Of course, when the arduino reads 1024, it won't know actually what the weight is, just that it's the max readable.