What is Shared Hosting?
Shared Hosting is where lots of different website are all sharing and running from the same server. This is the cheapest way to get yourself some webspace. These are also very easy for a webmaster to manage as this is all done from a control panel.
Shared hosting is a good place to start if you are getting into the web. Its cheap and there are a range of facilities that can be availble in different shared hosting packages.
Linux Shared Hosting
This is the best option for shared hosting unless you need facilities such as .asp, .net and MSSQL. If you require these you should use Shared Windows Hosting.
The operating system of your home machine has no affect over the package operating system you choose.