The Aguilar surname dates back to the 14th century Spain and came over to the new world with the conquistadors. Branches of the family ended up in Cuba, Puerto Rico, Mexico, Peru, and Louisiana and New Mexico. The first place to start would be with your parents, grand parents and if still alive, your great grandparents. Find out when and where they were born, the names of their brothers and sisters (your aunts and uncles) and any other interesting information. Write down everything and anything you get, then see if you can tie in with some of the people doing genealogy studies on this web site or one of the others online research sites. It takes patience, understanding and time, but it will be time well spent. Good luck in your quest.