I am interesting in buying an existing web hosting company , do I need to have expert knowledge of computer programming ? If so , where can this be outsourced ?

The skills required depend on the type of application you plan to host. If you plan to host a LAMP (Linux / PHP) then some knowledge of those products would be very useful, if not mandatory.

If you choose to do Windows .NET hosting you may want to get your MSCE, and other such certifications. I would recommend that you familiarize yourself with how a hosting company operates, as you will need some business skills, marketing skills, as well as some negotiation skills.

This all assumes that you plan to build a bricks and mortar hosting company. If you plan to simply outsource, then you need some analytical skills, and social networking skills or connections.

You should analyze the company you are planning to buy, and determine what technologies are in use, and what the clients want / use.

You need good knowledge of network systems, system administration, client server architectures, web servers and security. You also need to deal with server farms.