Question : Problem: A question regarding using a MAC BOOK wifi

Lets say I go out and buy a Macbook or any Apple computer with WIFI capability.
Can I instantly have the Apple Mac Book connect with my D-Link Router that I have at home or do I have to buy some other device for the Mac Book to get Wireless Access?

I think that device is called Apple Airport or something like that.

Answer : Problem: A question regarding using a MAC BOOK wifi

Apple have branded their WiFi  and called it "Airport" however this is just another name for WiFi ..
All new Macs come with in-built WiFi and support all the main formats 802.11b, g and n
As long as your D-Link is a recent model  then the Mac should work perfectly with the D-Link.

To be sure .. just go to the D-Link website and check the supported protocols for your router.