Naturalization is one of the ways you can become a U.S. Citizen. However, the process is harder than you think. There are many steps that you must fulfill in order to have your ultimate application approved. You are eligible to apply for Citizenship through Naturalization if you:

• Are 18 years or older
  
• Have been a permanent resident for a certain amount of time (usually 5 years or 3 years, depending on how you obtained status); 
  
• Have been a person of good moral character; 
  
• Have a basic knowledge of U.S. government (this, too, can be excepted due to permanent physical or mental impairment);
  
• Have a period of continuous residence and physical presence in the United States; and
  
• Be able to read, write, and speak basic English.​

You may be waived from the above requirements, if at the time of filing, you: 

• Are at least 55 years old and has been a permanent resident for at least 15 years; 
  
• Are 50 years old and has been a permanent resident for at least 20 years; or 
  
• Has a permanent physical or mental impairment that makes the individual unable to fulfill these requirements. 

• Ensure that you meet all the eligibility requirements before submitting the application
• Fill out Form N-400
• Fill out the necessary waivers of inadmissibility (if required) 
• Ensure that your fees are correctly submitted and represented, using separate checks if necessary
• Review the Naturalization interview with you, going over the commonly asked questions
• Accompany you to the interview 

USCIS provides a comprehensive PDF file on the Naturalization process.