Macbook Air - blocking pop ups and websites

I just recently got a Macbook Air and when I use Safari I have checked - block pop ups but when I use various websites it opens new webites and popups that I don't want. Lots of the websites are mac related but I am not wanting those to keep opening when I am looking at a site. How can I resolve this?
Elmerglue

AdBlock for Safari.

Sounds more to me like you've picked up some adware. Use this to clean your machine of some possible adware: AdwareMedic