I am a 38 yr with three sons of my own, and I am tired of not being able to tell them what nationality we are. I need to know how to obtain my adoption records. Does anyone know of an easy painless way to do this?

You did not mention what nation you are in US, Iran, Mexico and so on.

Next if in the US what state you are in.

But in most states all records are still sealed unless there is some need for emergancy medical reasons.

And you are what you are, if you were adopted, they are your real parents, not the sperm donor who did not stay around.

And if you were born in the US you are American, if you were born in the Southern part of the US, you are also blessed.

Cyn, I would start with ISRR. International Soundex Reunion Registry. Then if you are in the states, I would check to see if there is a state registry that you can register with. You deserve the right to know your heritage. As well as medical information if they were kind enough to leave it for you. In many states, rulers are realizing the importance of opening access to original birth certificates. It is my belief, as an adoptee, I have the right of any other American to access my vital record, for instance.
Also, if an adoption agency was used, you can contact them and receive what is called your non id information. This is whatever information that has/was left for you in case you were interested in knowing about your first family. It is your history. It is your story. And you own it. It is my hope that this information is available to you for the asking. If not there are plenty of search angels that maybe able to guide you and support you in your endeavors to know your truth.
And yes, your real parents are the ones that raise you. One does not replace the other. It only defines the soul that is searching for answers.

Please do not listen to any negative people in this world. Especially being an adoptee, finding your birth family, or the what if's.
You are an adult. Your birth mother and father are adults. He/she maybe searching for you. And it is up to you and your belief system to decided what is best for you and your first family and to search for him/her. There have been many happy reunion's. Don't let anyone tell you differently.
There is an adoptee support group: Yahoo! Groups as well as many others. You can do a browser search on the yahoogroups.com website and or googlegroups.com website.
May I suggest you start of there. It is very helpful to share your experiences as well as read other's experiences who have undergone the same things that you yourself have undergone. I have. And receive support and assistance in your search process.
Also, most adoptees decide to register with Adoption.com - Information on International, Domestic, Child & Agency Adoptions, Stories, Laws -. If there birthfamily is searching for them, in all likelihood they have registered there as well. Just leave a current and update email address. Because it may take time and you don't want to miss the opportunity by not having an active email address if he/she does try to find you.
There are many support groups for adoptees as well as birth mothers, and adoptive parents. More and more adoptive parents are realizing the necessity of knowing and having good communication with their child's first parents. It is no longer taboo. And open adoptive the mainstream today.
Please check at the Yahoo! Groups site and put in adoption in the browser search. Select a group that will assist you in your state or the state of where the adult adoptee was born. You will see how many people are in the same situation as you are in. Not everyone is negative about adoption. Some are, and you have to feel sorry for them.
But I am sure you have lived quite long enough to realize there are people out there that just want to discourage you. Discourage you from wondering, discourage you from searching yourself, discourage you from your getting your information, discourage you from searching and reunion.
Everyone is different. Everyone's path in life is different. You may just find your first family waiting for the past 29 years to find you. Please do not let anyone make you feel that you do not have any rights to search for him/her and find out if they are willing to reunite and or speak with you. He/She is an adult now. You are an adult now. And you and they can make up there own mind. There are millions of adoptees such as yourself searching and seeking a reunion. There are millions of birth mothers that are searching and seeking a reunion.
Get the support that is long overdue with a support group. Register with Adoption.com - Information on International, Domestic, Child & Agency Adoptions, Stories, Laws -, you never know if she/he is desperate to find you. Register with ISRR, International Soundex Reunion Registry, ISRR . com , Index of Search and Reunion Resources. And find out if there is a State run registry were the you were born or if you can register with them.
Again, he/she maybe waiting for you to register. And maybe not. But you never know until you find out yourself. You have a right to find out. I have.