Hmm, well saying you want "warez shit" really isn't a good way to get the advice you want.
In brief, usenet these days has two uses. Searching for and downloading binary data, and also it's original use of chat. To do the former, you need a usenet server subscription and a client, and a way to find the data. I use binsearch.info and nzbmatrix to get nzb files (equivalent to a .torrent file - it's an ugly system technically and also to use, but it's all based on VERY old technology so understandable) and hellanzb or nzgbet to download the files references by the nzb file. These are both client / server console utilites, not sexy gui's, but I have had some luck with lottanzb as a gtk2 based front end for hellanzb. As for the usenet server, go find one you like. Giganews and similarly flashy sites are a rip off though - I use Astraweb at the moment.