For a Spanish visa the following documents are required:-

2 Schengen Application forms dully filled out and signed.

A valid passport i.e. a passport must be valid for the intended period of your stay in Spain with at least one blank page to affix the visa.

2 recent photos passport size with a white background. Staple one photo on each of the application forms.

Letter of acceptance as a full time student from Spain's University/School with details about the fees, course duration and length of stay.

Also, a Health Insurance coverage for health/accident with a minimum coverage equal to €30,000 during the planning period of stay in Spain.