I'm from Canada but in theory the hunt is the same.
For my 3 year degree I ended up winning scholarships to pay for all of it and have money left over - and I was working full time. (I won a $13K scholarship plus 2X $500 scholarships, a bursary for $800 and a free course)
Places to ask/look:
Federal government websites
Provincial (state) government websites
Your school
Your local legion
google - seriously, there are tonnes of scholarship listing websites
Banks - they often run scholarship contests throughout the year
Your school's student union
Tips:
Play up your volunteer experience and get more - make sure it is varied and makes you seem like a "whole person"
You don't need an A to win scholarships
Apply for EVERYTHING but read the fine print and always follow the rules strictly
Get strong good references
Follow up each application to make sure they received it
Get your school awards officer on your side to make sure you apply for everything and to help you with applications
Apply for bursaries even if you don't think you qualify unless you expressly fall outside their income brackets
Scholarship hunting takes a lot of time but is obviously worth it

I turned it into a hobby and it paid off. A lot of people apply willy-nilly, but if you are organized and a little obsessive about it, you can find a lot of good money that isn't always advertised or well-known.
Good luck!