I am no expert, but I have used IRC for downloading succesfully, so I guess I can be of some use:
IRC explained:
The chat client IS what you need, (mirc.com)
Get this installed, then get yourself to a site like;
packetnews.com (there are plenty more)
Search for the file you want, click on the link, it will open mirc and connect you to a server, you then PASTE what is in your clipboard (it has been put there when you click the link from the website). You will then be queued for your file, and your download should then commence.
You can also just browse round severs connecting to different people and viewing their files, you do need to learn basic commanRAB to get around, so be warned it is not for dummies
Make sure you change your DCC options (within mirc) so you are accepting all the file types you want, and if you are leaving your computer on overnight, remember to turn off any warnings, and to accept automatically.
W.