In order to apply for Schengen visa the immediate required documents are the application form with the enclosed letter mentioning the entire plan and purpose. The personal covering letter with the entire plan should be clearly mentioned for your visit to the country.
For working professional Schengen visa can be obtained only if you have the leave letter or no objection letter from your employer. If you are a student then you must have the no objection letter from the school or institution.
Cased of flight itinerary or flight reservation for visa application should include the required flight and airport information along with date of travel and flight names. These details should be obtained from a qualified travel agent.
Hotel booking documents, Proof of accommodation and other Identity based documents are mandatory along with valid health insurance covering a minimum of €30,000.