about downloading the selected information

[woaibeiyang]

I have a problem to download the information from url 
http://www.ncbi.nlm.nih.gov/sites/entrez. Because it is impossible for me to 
add searching material to the url to construct a new url and then visit the 
website.
I have the searching material, however I could not find the way to deal with 
this problem. I want to know how can I do this problem with python and which 
part of knowledge should I view first? Thanks!