NCAA - www.ncaa.org

NAIA - www.playnaia.org

You can set up a free profile as early as your 8th-grade year and add your information to it every school year. 

You need to register with one or both of these institutions in order to be eligible to play sports in college. You will find eligibility criteria as well as a list of schools that use a particular registry (i.e., either NAIA or NCAA). You can also see a list of showcase tournaments for NAIA for greater recruiting opportunities within the NAIA schools, rules on letters of intent, signing dates, etc. for both NCAA and NAIA.