There are number of panels to manage your server but one the panel which is used vastly is virtualmin. Virtualmin panel is good and easy to handle due to its simplicity. If your budget for server is limited then you can go ahead and install this panel to manage your domains/websites.
Once you have a plain server with centos installed on it, you just need to follow below mentioned steps to get your virtualmin panel up and working.
Firstly you will need to update yum to its latest files, using this command.
yum -y update
Then you will need to install perl on your server to make your applications run smoothly on the server.
yum -y install perl
Next you will need to install wget on the server to easily install wget respository on the server. To install wget you just need to fire this command.
yum install wget
Now, you will download virtualmin pack from official site of virtualmin using following command.
Once you have downloaded everything, you just need to fire this command to get your virtualmin installed on the server.
You can now access your panel using https://yourip:10000