I'm afraid that all this VOIP, VPN and SKYPE stuff is way over my head.

How does it impact the casual internet user who only wants to use a web browser and send/receive emails, like me?
Actually, most of the blocking technologies used to catch Skype and VPNs, which themselves you might not use, can also degrade performance of normal web browsing activities.
Skype and VPNs both will pretend to be normal web activity in order to try to get around blocking technologies. Therefore, in order to completely block them, the ISP will have to monitor normal web browsing ports and do deep packet inspection on each web request. If something on the line looks like it may be a skype or vpn request instead of web request, it kills the connection. If the inspector software makes a mistake and accidentally kills your normal web browsing connection, to you it seems like the server you are browsing to is down. The end result is that you feel like you are using a flaky connection. Also, the process of simply digging through each packet for skype or vpn traffic will add latency to the connection which then also unnecessarily slows down your browsing experience.
Having said all that though, Skype is a relatively casual internet use (text/audio/video chat with family and friends). In fact, it's not usually the business user who would be benefiting from the use of Skype as business tends to use more standards based voip solutions based on the SIP protocol (which is also blocked by the way).
VPNs are more of a business use, but it is also used by the more casual user to try to get around Skype blocking technologies.