Hostel in downtown Amsterdam, cheap, and close to transports?

Hello,

I plan to move to Amsterdam soon. The plan will be to stay at a hostel for a bit while looking for an apartment and a job.

My question is : what would be the most appropriate hostel in Amsterdam for me? It would have to be more or less downtown, not too far from supermarkets and such, and accessible through public transports.
To sum it up, it would have to be perfectly located in order to look for a job and an apartment without having to have a car, etc.

Does someone know such a place? Or maybe someone knows about some other sort of cheap places to stay in this situation?

Thanks for your help.