What did early Nomadic families and townspeople offer eachother?

I'm not sure what you're asking here, if it's about early societies or the differences between settled communities vs. nomadic ones, or something else entirely :-)

The most important thing in nomadic communities is the mutual responsibility every member of the community shares. It is this feeling of belonging to the larger circle that ensures your well being and others'. You have to be sure you will be protected with everybody else, and that you are a part of the caravan.

This sense of community is of course a part of settled societies as well, but as we can see in the more Westernized communities, the tribal responsibility is diminished, and the nuclear family basically takes care of itself. 

By their very nature, nomadic peoples raise sheep, goats and cattle. Townspeople work in agriculture and simple manufacturing. Therefore the nomadic peoples sold the by products of what they were raising: meat, skins, mlk, cheeses, wool, etc. and could buy clothing, tools, agricultural products, etc. from the town people.

Well, a first answer I can see is rather obvious : meat against vegetables.

Nomadic families in Africa, Middle East and Asia were cattlers. Sedentarian cultures are built around agriculture. This first exchange is for subsistance.

Is that OK with you ?