Once you marry, you initially would need to submit an alien relative petition II-130) to the U.S. Citizenship and Immigration Service office with jurisdiction over your place of residence in the United States. On that application, if it is properly noted that your wife is overseas and that the consulate in her home country will need to be notified of the approval, the case will the be transferred to the National Visa Center, and ultimately to the consulate for her immigrant visa interview if all the paperwork is completed properly.
Certainly, it can be helpful to have an experienced immigration lawyer assist you in the process. You may wish to consult with someone through Avvo, the American Immigration Lawyer's Association (www.aila.org), ImmigrationLawHelp.org, or http://www.justice.gov/eoir/legalrepresentation.htm.
Ms. Doerrie's answer to your question is general in nature, as not all facts and circumstances relating to the specific person(s) and situations involved are known to her. Ms. Doerrie recommends consulting with an immigration attorney regarding your specific facts and circumstances prior to making any legal decision or submitting any form or application. This response does not create an attorney/client relationship.
IF you ar.e living in the United States, then you would file an I-130 petition in the U.S. for consular processing in her country. Once approved the application will be sent to the national visa center. It will then be sent to the post in her country. She will then be interviewed in her country. If you are living in her country you can file a Packet IIIA with the US consulate which will include the alien relative petition
You should go to the USCIS website and look up the filing location for where you live on the I-130 instructions. However, I would seek the advice of a good immigration attorney first and also look into how long her overstay was or for any other immigration violations you might not know about.
If you are a citizen and your fiance entered the U.S. on a tourist visa, then it is highly likely that you can concurrently file her visa petition and she can file her application to adjust status. Based on the limited information you've provided, she would not have to depart the U.S. I strongly encourage you to retain a lawyer to represent you in the process.