Ho there,
i have windows 7 Family edition premium on my pc and i installed IIS i created one website and now i would like to host my websites on my PC tha everybody can see it.

I heard that IIS allow you to host only one website.. and that apache is better for web hosting.

Is there anybody who could explain in a easy way how to host web sites on my PC

IIS on windows 7 supports more than one website, and would be the least of your problems.
It is your home connection to the internet that may or may not limit the amount of websites you can host.
Ideally you would have a STATIC IP address so that you can point domain names to it.
If you do not have a STATIC IP addres, you would need the services of something like dynamicdns.com
Next your home connection - router, adsl/cable modem would need to port-forward web requests to the commputer on your home network that has the website(s) - so that computer would also need a static IP on your LAN.
Next, your IIS websites would need to have hostnames bound to each site so that IIS knows where to direct each request.

It is no small task if you have never done it before.