DNS in-house or at ISP!!!!

I understand that you have to have DNS to use AD. My question: What are the implications to having your DNS provided by your ISP as opposed to having it in-house. How should I configure AD if I use my ISP’s DNS servers? I only have a Windows 2000 server ( was my NT 4.0 PDC) and another NT 4.0 BDC running exchange. I have not yet configured AD. Are there any specific “do’s and don’ts” with this setup?