4 questions?

[BeNe]

I´m not sure why you asking such questions, this is the minimum knowledge...but OK.
FTP: 21 / 20
Web 80 / (SSL) 443
SMTP 25
POP3 110
IMAP 143

Quote:How to make my domain to get forward to Debian(to work on my server)

Create a correct DNS entry to your Server.

Quote:How to create sub domains for users?

This is a extra point in ispCP in the Menue.

Quote:How to create a registration page?

Build a Hostingplan (is also in ispCP included, more or less)

Greez BeNe