Doing rollers

I have curly hair and I want an easy way to straighten my hair. Some of you may or may not be familiar with a thing called a "doobie" they put your hair in rollers, put you under the dryer and then take your hair out and wrap it around your head with bobby pins this achieve straight hair with a bounce to it that can easily be flat ironed. I have verrrry curly hair and have found that this works, so my intentions are to do my hair in rollers sleep with them then take them out in the morning before school and flat iron them. Now... my problem is I don't know how to do rollers. Help please!