So, did you ask your web host? That's always the first best approach to issues like this.
Don't they have a help section (forum) or FAQ that covers this? Did you search it? If not then change web hosts.
IF you are attempting to do this "all on your own" then the first thing you need to do is buy a few books about running a web server.
This is really a "basic operations question" and, not to be unfriendly but to steer you in a more fruitful and ultimately better path, you need to learn how to approach issues such as this. First, check your web hosts knowledge base. Second, post a question to their help forum if they have one. Third, file a support ticket. Fourth, check for online tutorials by searching keywords + "tutorial". Fifth, get a book that introduces you to the issues you will face. Spend some time at the local bookstore.
You know the old saw: "Hand a man a fish and he'll eat for a day. Teach a man to fish and he'll eat for a lifetime" . . . if the fishing is good. ;)
Sorry, no fish for you today. Only fishing lessons. :P