> i try to download a certain pages from 
> www.imagenetion.com, but i don't know how download 
> exactly one group of pages, for example i chooce an 

First start from a desired page, like
<http://www.imagenetion.com/smith1.htm>

Then, use filters to only accept what you want to:
-*
+www.imagenetion.com/smith/*
+*.jpg +*.gif +*.png +*.css +*.js

And then, please restrict your bandwidth, because 
images generally takes a LOTS of bandwidth!:
- 1 simultaneous connection
- if your bandwidth is FAST, limit it 
throught "maximum transfer rate" option