How do I judge the quality of 'green' beans? I'll have a chance to visit some coffee farms in the coming months, at which time I'll be able to purchase small amounts of 'green' Arabica beans. The only experience I have with purchasing these types of beans in the past has been online, and I'm not particularly certain that the beans I received could be considered fresh.

Now that I have a chance to actually see what I'm getting before I get it, what should I look for in a fresh bean as far as quality? Are there characteristics that I can look for which indicate that (if properly roasted) the bean will produce something good? I can only compare with what I've bought previously, which was of dubious quality, so I'm not entirely sure what to look for.
I have been purchasing everything from cheap beans to rather pricey beans and what i discovered while buying the more pricey (and higher quality) beans was that the fragrance of the bean is somewhat stronger and can actually smell of more than just the usual grassy fragrance. Notes from fruits and nuts are not unusual and could be a indicator of somewhat higher quality coffee.

I have no scientific proof of this, and while even expensive coffee can be bad, it is my empirical approach to determine what could be a step up in coffee quality.

Apart from that i have to admit that its hard to determine the quality of the bean before it has been roasted.