L.M.
In 2009, were you "legally" separated? You also say you were separated for 2 years, how did you file last year? I would think it would be the same this year. The reason I ask "legally" is because if there was no legal document than the IRS considers you married. Based on your questions, it sounds like your husband is filing as "married filing separately" and wants to make sure your not claiming the same deductions.
Are you using a tax preparation software? If yes, it should help guide you through this. Try using their on-line help. You can also try calling the IRS.
If your just trying to do your taxes yourself, you may want to consider hiring a tax professional for this year due to your unique circumstances.