Plug ins

I need very basic help please. when I download a plug in
and use the “wizard” to extract, do I just click on “extract files” and that should be all I need to do or do I need to double click on the folder and show the extracted information in the same window ( not very clear I know) I am having trouble getting plugins that I have downloaded into my blog,and I have asked this question before but the answer I got was to do with the FTP site, and I now know its the downloading that I am not doing right, sorry to bother you all again. tks