I was placed on medical leave for the mojority of the year and was unable to work. Before that I was working but know I earned very little income because it was pretty much the beginning of the year. I need to know if there is a certain amount of income I had to earn in order to claim my children.

You must have earned income to claim the Earned Income Credit and the Child Tax Credit.

Claim your children unless you do not need their exemptions and someone else can legally claim them.