If you applied for a green card through your spouse in the 2 first years of your marriage, you will need your spouse to file for removal on condiotional status on your resident card. To do this, your spouse will need to fill the form I-751 before the 2nd anniversary of obtaining your resident card. This is extremely important and must be remembered as you could loose your resident status if you do not do it within the right time frame

As an example this means that if you received your card on the 1st of januray 2007, you will file for premanent resident status without condition between the 1st of october 2008 and the 1st of januray 2009.
This simply means that 3 months before your resident card expires , you will apply for a new card. This cost $275, and you can download the form on the uscis website. www.uscis.com