See this website for I-130 filing for immigration visa application:
http://www.uscis.gov/i-130
See this website for K-3 visa:
http://www.uscis.gov/family/family-us-citizens/k3-k4-visa/k-3k-4-nonimmigrant-visas
I-130 filing is needed for both immigration visa and K-3 visa. You may hire a lawyer to help you, if necessary.