I didn't file taxes in 2008 because I was not employeed, I made no taxable income. But,I did purchase a home.?

If you had no taxable income, there was no point in filing. If you qualify though as a first time buyer for that credit, then go ahead and file - now you have a reason to. Since you didn't file in the first place you won't be filing an amendment, you'll file an original return.