on linux mail, dns, http server

["judee itoy" <kiss1@cebu.pworld.net.ph>]

  hi !  my only experience w/ linux involves only machines w/ dynamic IP's and i was wondering whether someone can help me w/ a few questions when you really have a domain of ur own.

1.  i am setting up a box w/ a static IP (say a.b.c.20).  and w/ a just registered domain (say kewldude.com) .  but when i do a _$whois kewldude.com _ , or whois from internic, part of what i get is this,

   Domain servers in listed order:
   NS1.MYISP-DNS.NET           a.b.c.3
   NS2.MYISP-DNS.NET           a.b.c.4

Question : Does this mean that my ISP will have to make a pointer on their DNS servers to me (a.b.c.20) ?

2. During the debian setup/install procedure, theirs that part where the program will ask for the "machines name" and then the "domain name".  What's the right way of answering this anyway?
   (a.) machines name is "kewldude" and domain is "com"
or  (b.) machines name is "some_name" and domain name is "kewldude.com"

3.  Since the machine that I will be setting up will act as a mail server and web server for kewldude.com, do I also need to set up its DNS in a way so that it will be SOA for kewldude.com ?

thanks a lot and i hope someone can help on this,
judee