Document required at Airport on Business Visa

I am vignesh from South India.

I received a job offer letter from one of the qatar company.

I signed it(offer letter only),scanned & send it(offer letter only) to qatar company.

After 2 weeks ,my qatar employer has sent scanned copy of Business visa to me.

I have the following questions :

1)will i need to take a flight to doha just with business visa print copy or need any thing else ?

2)For visa endorsement on my passport at doha airport, what documents do i need ?

3)Till now ,i not yet signed employment contract and also i not get certifications yet from qatar embassy in india and also i have not undergone medical test in india because my qatar employer have not told anything about it(i.e certifications,medical test,employment contract)----my questions are----whether these are (i.e certifications,medical test,employment contract)needed for business visa or not ?

4)my qatar employer just told that --- you will be at business visa for testing period of 3 months and thereafter we will provide you resident visa ----whether it is ok ?

5)Any other tips for new comers like me at the Doha airport ?

regards & thanks

vignesh