Once you have registered a domain name, the domain needs to be hosted somewhere.
I would recommend a hosting service within the country that you live in, especially if your main market is within that country. If you sell or advertise primarily to another country, you should consider a hosting provider in that country.
The reason for this is speed. Slow websites tend to decrease the experience of your website for potential customers. The faster it is for them, the better their experience - the stats are in on this... if your website takes more than a second or two to load, the majority of customers coming to your site will go somewhere else before the page has finished loading. You've probably noticed yourself that long page load times tend to impact your willingness to stay on a site.
The hosting provider I use is in Melbourne and is connected to the Telstra backbone - this ensures high speeds within Australia and the highest possile speeds for an Aussie site for international visitor.
Note. Hosting providers charge an annual fee to host your domain on their web servers.