Here are one by one steps for you to start building your own site -
1. Purpose of site - First decide what is the purpose of developing the site, what is it's use to you.
2. Domain name - Once you are sure about the purpose and use of the site then you should think about the domain name for your website. Find the catchy and small domain name which will be remembered by the users easily.
3. Platform for web design and development - Decide on which platform you would like to design and development. You can create the hard coded site or you can use the in-built CMS like WordPress, Joomla for the web development.
I would suggest, if you are new to web design and development then use the CMS (Content Management System). There are so many themes available which you can install and just need to replace your contents.
4. Web Hosting Service - When you will become sure about the platform then search for the web hosting service which is suitable for you. Study and review the web hosting plans of various providers and after that make the list of top three in the list. If it's suitable to you then try the hosting service for some trial period and after that sing-up for the hosting service. ]
Make sure the hosting provider will fulfill your disk space and bandwidth usage.
5. Web design and development - Once you've signed-up for the web hosting service then start the web-design and development.
6. Upload the contents - Upload all the contents under the web hosting service panel.
7. Check the site is running properly or not by adding the entry in the hostfile. So before getting site live, you should make sure it is loading properly or not.
8. Update the nameservers - If testing is done properly then you should update the nameservers for making the site live. You will need to contact your hosting provider for nameservers and for updating them you should contact the domain registrar.
After updating the nameservers, it will take 24 to 48 hours for DNS propagation.
You've 3 options you can start as a reseller and keep your costs down, usually the best option if you dont know how to administer a server until you've got a decent amount of knowledge.
When you become a bigger provider you can then moving to a VPS or a dedicated server, the only flaw when moving is you are going to need all your customers to move aswell unless you decide you want to keep them with the original provider and setup a second one... this is why most people starting out may start with a VPS/Dedicated server to save them the hassle.
Your best bet for something quick and easy is to go with a reseller service from another bigger webhosting company , the prices in the market are fair and you can get quality service for less than $20 a month.
I would definitely start out with reseller hosting and either with a Wordpress or WHMCS theme as they are the easiest to manage. The biggest mistake you can make is setting your goals too high. You won't make a lot of money, maybe nothing at all in the first few months. Your focus should be learning as much of the industry as possible. You also have to understand the most common issues your client might face and how to solve those issues.
I think the most important factor when starting a Hosting Business as a one-man operation is to minimize costs as much as possible. Who knows long it will take until you make a profit and even then it won't be much for the first year or so.
Try to cut costs everywhere. I would advise paying for WHMCS tho as it's essential in my opinion.