Arlit is a Saharan version of a boomtown: Uranium mines in the desert have given it a recently-thrown-together look and feel. Since Arlit is on the main road to Algeria, the town is quite a busy place (when the road is open at least, when it is closed you don't need to be here). There are many things to be bought and sold, there are banks here, there are some bars. There is also a real tourist office here! On the other hand, the banks do not always have money, the bars do not always have beer. The hustlers who buy and sell are always there and you will not have trouble spotting them.
When you arrive you have to go to the police and leave them your passport. You can get it back when you are ready to leave.