If you're specifically referring to college scholarships or grants, (and you live in the U.S.), I would recommend starting by contacting the financial aid department of the school you're attending or planning to attend. Next, apply for the FAFSA online. There are thousands upon thousands of scholarships out there - you can find them by looking at scholarship books at your local library or checking out a website like scholarships.com
If you're asking about how to apply for them, I would say the two biggest factors to receiving a scholarship is fulfilling the requirements and writing a REALLY GOOD essay (most will require you to write one!)
Search for a guide on writing scholarship essays on Hubpages? :)
Most of the qualifications will be based on the field you're studying, the university you're attending, your grades, and sometimes your ethnicity, gender, and other demographics. Hope this helps! G'luck!