Prospective SAP trainees can follow basically three streams to begin their SAP career. This largely depends on the interest level, career aspiration, experience in their careers etc.
SAP has a large and extremely varied range of functional training ranging from Financials, Materials Management, Sales, and Planning etc.
The basic requirement is experience in the respective domains to which the SAP trainee is aiming for. Materials Management experience for SAP and so forth.
ABAP and NetWeaver components are the target areas for those with a technical (development) bent of mind. Every SAP project has a large number of technical resources that work on a wide variety of roles. Development experience is helpful but not mandatory.
Resources who have experience in installing, managing systems and landscapes can easily train themselves to become SAP Basis resources. The landscape of SAP changes rapidly and it is an extremely growing area within the SAP career.