import bulk users ad

Guys,

I would like to get some more info about the import users through a csv in Ad.
First, i did read some fine articles(like this: http://www.computerperformance.co.uk/Logon/Logon_CSVDE_Bulk.htm) but most of the time i get more questions after reading those and i still cant do the trick.

question 1: i would like to find out what attributes i can use in the csv and what their purpose is

question 2: how should i read the DN attribute, it starts with the name of the server or the domainname?

question 3: what if i want to create users in a nested ou(OU: users: OU: management), how should i do that

thanks for the replies and help