How to choose basic health insurance in the Netherlands?

You can check this website: http://www.zorgkeus.nl/

It asks you some basic questions about how much of a deductable you would like, whether or not you would like dental insurance and so on. You should be able to use Google translate to help if need be.

As for the health insurance subsidy (zorgtoeslag), the above website says the criteria to receive it are:

• You're 18 years or older
• You're a Dutch citizen or legally staying in the Netherlands
• You have a "basic" health insurance plan as specified in the law
• You are not in prison, in active military service or are not opposed to insurance due to religious reasons
• You have a maximum income of (in 2014) 28.482 as a single person or 37.145 with a partner.

The amount of subsidy you could get depends on your income (as shown in the graph on the same webpage): http://www.zorgkeus.nl/informatie/zorgtoeslag

The simplest way to deal with these things is to get some help from a local once you are there. If a few euro / month subsidy is going to make or break your decision to study in the Netherlands, I would advise against going there. The rules around these things tend to change every couple of years, sometimes favorably and sometimes unfavorably.