I will now outline the ULTIMATE way to download from Usenet, which itself is the ULTIMATE way to download from the internet.
It is slightly more complicated than the average download method, and you will have to pay a little bit per month, but it is TOTALLY worth it. In other words, you have to make a little bit of effort, but the payoff is that you will find an absolute gold mine of information and data.
The first concept to introduce is the concept of the NZB file. NZB files are packages which contain references to files posted on Usenet. All the important releases on usenet come with NZB packages, which simplifies the process of downloading what you want.
Separate services exist to catalog the NZB files which exist. A free option is www.binsearch.info . Check it out and type something you want to download, for example "Ubuntu"
Here is a link to the results page: http://binsearch.info/?q=ubuntu&max=50&adv_age=50&server=
As you can see there are a bunch of posts from the last 50 days, including the full DVD at over 4 gigabytes and a DVD rip at around 700MB. To download the NZB, simply click on the checkbox beside it, then select "Create NZB" from the top. This will download the NZB file to your computer.
You can't do anything with an NZB file, however, without a Usenet Client!
The best free option is called "GrabIt", and you can find it here:
http://www.shemes.com/index.php?p=download
Once you have that, you can open the NZB file in the client, and it will automatically queue up all the files in the package.
You can't actually DOWNLOAD anything, however, without an actual Usenet account! After many years of using usenet, I have found the ultimate, and it is Giganews.com. Click on the following link for more information, you can basically max out your internet connection and download the whole internet for $20 per month:
http://www.giganews.com/?a=aaa
Yeah it costs a bit, but it's so easy to the value back!
If you can spend less than $1 per week, I also recommend you go for a pay service to find your NZBs, the best one I've found is http://v3.newzbin.com. This service is more organized than binsearch.info, and has a community built around it of people who rate releases, spot fakes etc.
Welcome to the world of Usenet!!! Good to have you on board!