Domain Name

[Alan]

Can anyone help as i am new to creating a web site.
I have a Domain name parked with one Company and have
just opened a hosting account with another Company.
I am told by my hosting Company that i now need to
arrange to have the DNS entries for my Domain modified.
I have all the details of what to modify it to but no
instructions how to do it. Can anyone help me please.
Many thanks Alan