All torrenting is, is it breaks down the file into different parts, and multiple people (seeders) upload the parts so that you can download them. The more seeders you have, generally means the faster the download speed will be.
All you do is click .torrent file, open it in a torrenting program (uTorrent) and then download.
If you are getting slow download speeds it means you either
1. Have a slow internet connection
2. Not enough seeders, or a too high seeder/leecher ratio (How many people are uploading the file versus how many people are downloading it. If you have too many people downloading it versus uploading it, you'll have a slow download rate)
3. Your ports on your router aren't forwarded- the most common reason for slow download speeds.
In order to forward your ports, you need access to your router's username/password. This is a website that'll help you get it set up if you know your router's manufacturer/model number.
http://portforward.com/
There are pictures and everything. You just find the manufacturer, go down to your model number and click it. Then find utorrent in the list of programs that appear in the next screen. Then just follow the picture instructions.
http://www.mininova.org/faq
for more information about torrenting