Unless you have a very experienced in-house web server manager/administrator then I'd forget the idea completely.
There's nothing stopping you from arranging a managed server with a web host then hosting client sites on it, if you want to.
Likewise, some web hosts offer a reseller package which allows you to pay a sum of money and then sub-let/resell web host acounts under your own name.
A tutorial on setting up dedicated web hosting yourself is way, way beyond the limits of this forum although there are one or two of us who could rise to the challenge.
Perhaps this may put it into perspective for you a bit. I have a long background in server and network administration but I don't host any of my own sites myself. They are all hosted with dedicated web hosting companies who offer excellent service for a remarkably small yearly fee. I also tend to arrange individual hosting packages for my clients which gives them ultimate freedom to do what they like, when they like with their site, without necessarily having to come back to me.
Different designers operate in their own way, but unless I've read your question wrong, I'd sugegst you either look into leasing a managed server or arrange a reseller package with a large web host. If and when things go wrong with an account on a web host server, they are at fault and not you. If you run your own hosting company and something goes wrong, you are at fault and are answerable to your clients...