OMG, you are just in a similar position as my friend was last year. In fact, he joined a company that started with 3 employees and grew to 43 employees. I am not sure about the present condition of paperwork, etc.
Samvedan and C. Neyimkhan have provided a good list of work details above. The best solution is to start from scratch:
1. Determine the headcount.
2. Prioritize the employee payroll role. Ensure all deductions (PPF, etc.) are done as per the law. If not, start from this month.
3. Take charge of all old attendance registers, resumes, etc., and then start organizing everything.
A little more reference to your standing and we would be in a better position to help you.
Regards,
Jeff Davy