The best way to find those extra cash sources is to do your research. Check out the schools you are interested in and see what kind of financial aid is available in any form (i.e. scholarships, bursaries, awards). Check out their websites as all the scholarship information will be listed. Also check out websites that specifically deal with scholarships, awards and bursaries (a few are listed below in the Resources section).
Check with your local community resources and businesses. Many social clubs or businesses will sponsor students going into a field of study that relates to their club or business. Also, check with your parents to see if their company has any financial assistance for employees' children attending school.
Check out student financial aid contests. Some organizations promote contests that will help pay for tuition or books.
Review the application requirements and apply as stated. It is VERY important that you apply in the way that is stated on the application. Failure to do so might get your application tossed out, which is not what you want. Apply to as many scholarships, awards and bursaries that you can, but make sure you have the requirements listed (another way to get your application tossed out is if you don't meet the scholarship's requirements).