Selling Cell Phones

My friend exports cell phones, and makes good money off of it. He is willing to provide the sources he buys phones from, but our situations are a little different. He's from outside of the US, and so he buys them in the states from a bulk distributor, than sells them where he lives. I live in California. He says he knows people who do sell cellphones on Amazon and e-bay etc, and so along with that I want to possibly open kiosks in local malls, and hire a few friends to man them.

What should I expect/look out for? Any advice? Suggestions?