This is an excellent question, and I'm sorry it took me so long to get to it.

Before I go further, I can recommend Amira K. Bennison's The Great Caliphs and James Lindsay's Daily Life During the Muslim Middle Ages as resources you might be interested in looking at.

As you mention, Baghdad developed a well-known and refined urban culture (as did Samarra when the capital was there), but in other areas life did not change a whole lot or do much to reflect the urban sophistication. The majority of the people were poor agricultural workers; villages and small towns would have had merchants, religious officials, and probably an inn (caravanserai) for travelers if they were located along trade routes.

Certain services would have extended into the countryside -- given the trade networks, there would have been a wider variety of goods available, although many of these would have been luxury goods (so, for example, a woman might have been able to acquire golden thread to use in the embroidery on her wedding dress), so not necessarily everyday wares. There was also a postal system--the barid--that could get messages to and from distant locations (although, again, this would have been of limited utility to a population that could not read or write).

Living near Baghdad would actually have made life more difficult, since--as food could not be kept for long periods without spoiling--when the city was running short, agricultural districts nearby would be hit up for additional requisitions for the capital and/or the military (the latter being a wild card that tended to take agricultural products near wherever it was stationed).

Probably the biggest benefit is that for those select few who were demonstrably bright or talented, Abbasid society could allow for upward mobility--that is, students could be sent on scholarship to institutions of higher learning or join the civil service (the military, for much of this period, was not really open as it was populated by Turks from Central Asia who tended to hire their own). Such upward mobility depended highly on catching the attention of a wealthy or influential person who could then sponsor you or bring you to the attention of the right people, but it was, at least something.