Required CSV files.

Hello all
i have a scenario where in i have to create 100 users in Active Direcotry.
i heard that we can create users in bulk using csv files. As well we can edit user attributes.but i dont konw how to create csv files.

My Requirement is
1. have to create 100 users in AD environment
2. have to edit attributes for 150 users

can any one provide me the work around for this.

Thanks in advance.