If you want to make a presence online, with all the advantages and obligation that come from that, you have to get some necessary steps. Depending of your experience over internet they can be easy or they can be difficult, but with the appropriate help everything will be easy and you will only benefit from this activity.
Get your domain name
The first thing you need to do before anything else is to get yourself a domain name. Choose wisely because it's going to represent you online and must define you: it can be your name, your trademark or business name or your field of activity.
Depending the Top Level Domain (TLDs) you choose (they have their own rules), you will have to pay an annual fee to a registrar for the right to use that domain name or you can buy it "for life" (until you die, the interne dies or you decide to delete it). In some situations you'll have to buy similar domain name in order to prevent lose of clients or fraud, but you can find more information from tips for registering and choosing the domain name - read them and follow them.
You have to protect your domain name, so you have to pay attention to this thing in order to protect it from stealing.
Choose a web host
A web host is basically a company that has a lot of computers (usually they are called server farms) connected to the Internet. They are meant to host websites for clients - the numbers are in millions for each server farm - and all the internet users in the world are able to connect to it and view the web pages.
Design and test your website
There are some pros and cons of custom web design, some reasons why web design isn't for everyone and some reasons why most do it yourself website design are not successful, but designing a website is a necessary step: you need some web application to put on the server you've acquired.
The first thing you have to do in designing your website is to choose one programming language (as php, C#, JSP, Java) and a database (MySql, Oracle or others). The second step is to decide if you want to do it youself (using and customizing a free CMS - Content Managment System) or to hire an expert web designer to do this job for you. In the first situation you can get a free CMS to use for (as Joomla - there are some reasone why you should use it, Drupal or Wordpress), you configure it and you let people know your website.
In the second situation it's easy: you tell the web designer (or you decide together) what you want to do and you let him work and check his progress.
The final stage in designing your website is to test it. It's important that the website to work for all web browserr (or at least the most important as Firefox, Chrome, Opera, Safari and Internet Explorer).
Get your website noticed and get more traffic
When your site is ready, you can (at least) submit it to search engines like Yahoo, Google and Bing but you you will need some SEO experts in order to get your website noticed faster and to get it on the first page on search engines results. There are some ways to improve your website traffic, read them and use them along with the advice from someone that knows what SEO means.
Remember that if your site is already linked to by other websites the search engines and the internet users will find it easier, so do promote your website. You can do it yourself or you cah hire others to do it for you.
Create content for your website
The last important thing to do is to create content for your website - it's one of the most important things for a website (together wit its structure). It's the thing that make the difference between your website and all the other million of websited on the internet, it's the main reason the users and search engine spiders will return often and you'll be remembered for.