Decide which Spanish city you wish to live in. If you are interested in living near Moorish architecture, you might choose Cadiz, which also provides access to the Straits of Gibraltar and Morocco. If you are interested in Catalan culture, you might choose Barcelona.
Secure a job in Spain if you do not already have one. If you work for an American company that sends employees to Spain, you might already have a position lined up. If you don't, however, you will need a means of income. Craigslist.com operates pages with job listings in 11 Spanish cities such as Barcelona, Valencia and Madrid.
Apply for a work visa once you have a job lined up in Spain. Apply to the Subdelegacion del Gobierno in the city in which you intend to reside in through the nearest Spanish consulate, which is located in Chicago, Illinois.
In order to apply for a work visa, you will need the application form signed by your employer, your passport, 3 passport pictures, your job offer form, as well as documents showing your employer's financial, social security and tax documents. You will also need your company to submit a justification of your services and their need for a non-European employee. Finally, you will need to submit a copy of your degrees and certification forms.
Return to the Spanish consulate in Chicago when you receive the call that your work visa is ready. The consulate has to hand the visa only to you.
Look for a house or apartment to rent or buy once you have secured your job and your Spanish work visa. Craigslist.com and JustLanded.com can help you with this.
Purchase your plane ticket and start packing once you have secured all of the above.