just type in search bar :
site:.gov to display website with .GOV extension
site:.edu to display website with .EDU extension
site:.ext to dislay website with .EXT extension
site:site-url your-keyword to find specific page (url) with your keyword on specific website
in your explorer windows type : ( search yourkeyword on blog only)
https://www.google.com/#q=your-keyword&hl=us&tbm=blg
click on the link to see the result ( serach your-key-word only blog only)
#q=your sentence or key-word
&hl=us or fr for france or ca for canada and so on (google . com, . fr, .ca,...)
&tbm=blg (only blog !) it's useful to search only keyword on blog only !
&tbm=dsc (only forum !) it's useful to search only keyword on forum only !
&tbm=nws (only news !) it's useful to search only keyword on news website only !
&tbm=shop (only shoping !) it's useful to search only keyword on shoping website only !
More complex search here : Google Advanced Features - Google Guide