Getting internet is pretty easy here in NL and the basic (lower speeds) costs approx €20 a month. Of course the higher the speed you want, the more money you pay for.
There are plenty of providers thus competition keeps the price low e.g KPN, Tele2, Ziggo, UPC, Telfort, Online & Alice (and maybe more even). Some are held in higher regards than others, but having tried three different providers for internet I personally much the same to be honest
However not all of them cover all areas in NL and therefore you need to check what is on offer in your area. Easiest thing is to find one of the many sites which compare all current offers for your postcode. A good one is http://www.shopdigitaletv.nl/ and you can play around with the different options & packages for tv, internet & also phone which you didn't mention.; Generally getting services with one provider works out cheaper than getting different services from different providers
If you already have BBC, MTV etc then you already have an tv connection to a provider. As your housemates or rental authority (person) with whom that connection is with because you will be paying for it as part of your rent no doubt, and there actually may be restrictions about getting a connection with other providers if the landlord has one already for the same thing (e.g. if you want tv with another provider)
There are all different packages that providers offer again for TV and the more stations, the higher the cost. When you know which providers cover your area then go to the webpages and look for "zenders" (or even easier use Google translate) and you can see what channels are included in which package
Hope this helps, but if you have questions then just shout :)