Hey there,
can anyone one please explain what i can and can't do if i register a domain with EV1servers and other DNS services?
Also, say i register a domain somewhere and host somewhere else, what would i need to do to make my hosting service's e-mail and site work apart from pointing the nameservers to them

ev1servers doesn't provide DNS hosting, so what you can do is register a domain there and point it to another nameservers.

just point the domain to the hosting company nameservers and manage it from the hosting company.

what does DNS hosting exactly do then?? :S
can u explain it in details plz.. or point me to somewhere i can read about exactly what services they provide

google is your friend http://www.google.com/search?q=what+is+dns :D