Changing DNS
Any time you make a DNS (domain name server) change it takes around 24-48 hours to complete. During this proprogation time routers all over the world are updating their cache. This causes your site to be up and down randomly during the first 48 hours for different people at different times. Think of dns like a zip code. If you don't put a zip code on your mail the post office doesn't know where to send it. Domains are the same way if they don't have the DNS the internet doesn't know what server to send your request to.
Making The Changes
Every registrar has a different procedure for changing your domains DNS, however they are all done basically the same way. The welcome email you received from us provides you with the name servers you need to change at the registrar where you currently have your nam registered. We are always here to help with nameserver questions or setting host records properly. Feel free to contact us.