And explain to me why you couldn't have googled it? This is the kind of question that does not require a human to answer. I will paste what I wrote for the last person who asked this, since there's no need for me to waste the effort it would take to type it out a second time.
First off, don't choose some hostile client like BitComet, BitLord, Vagaa, Tuotu or Xunlei. Use a client that doesn't cheat.
I always try to make it as simple as possible, without boring you with details that you may not want to know about at the moment. I hope that what I leave out, you will look up yourself on an as-needed basis.
Unlike a traditional HTTP download, which downloads a file from a single fast server to your local machine, the BitTorrent protocol uses many sources (as do many P2P protocols) to distribute the file. These sources (for the most part) are users on residential internet connections. When you download a .torrent file and open it in your bittorrent client, your client sends a packet to the tracker announcing that it is there and requesting the IP addresses of users who have all or part of the file you are trying to download. Users who have all of the file and are only uploading to others are called "seeds". Users who do not have the complete file and are both downloading from others as well as uploading the data that they do have are referred to as "leechers". Once the tracker sends you the IP addresses of other users leeching or seeding the torrent, your client connects to them and requests the pieces that you are missing. Files are broken up into "pieces" to prevent data corruption. Each piece has an individual md5 hash. This means that if you receive a piece that fails the hash check, you only need to redownload that one piece, and not the entire file. This saves everyone bandwidth.
The advantages of bittorrent are many. One of the main advantages, however, is the fact that it is faster, and more reliable as the data is distributed more widely than an http download. Bittorrent is especially useful for those of us who are fortunate enough to have access to connections with high upstream (such as SDSL). <----- Not me
Now that that's out of the way, downloading a torrent is *much* simpler than people can make it sound. I'll admit, I have been guilty of unintentionally making this process sound more difficult than it really is. I tend to go on about details that many people simply aren't interested in.
All you really need to do to actually download the files that you want is to find a .torrent file from some tracker and download it. Just for the sake of this example, why not try something from http://legaltorrents.com
Download the .torrent file for something that interests you and save it somewhere, say, your desktop, for instance.
I'm using the uTorrent GUI ion this scenario because I hope that it's an effective subliminal way of getting people to use it. And yes, I am aware that it's not subliminal if I blatantly announce it like this.
You can open the .torrent file in uTorrent by dragging it onto the application itself or by going to File->Add torrent from within the uTorrent program.
You'll get a dialog box with some options, but all that you *really* need to care about is the save location. Choose some location that's convenient for you such as `My Documents`, `My Music` or `My Videos`.
Once you choose a save location, simply click `OK` and the download will begin. Just wait for it to finish and you can open your file by right clicking on the task and choosing `Open Containing Folder`. Either that, or simply navigate back to whatever directory you saved the file(s) in and open them directly.
Some basic things that you should be aware of are the following:
Seeds: These are, to be very brief about it, the people who have a complete copy of the file. They upload the file to you, but don't download anything from you (since they have nothing left to download).
Leechers: These are people who have not yet completed the download. They are currently downloading the file and simultaneously uploading the pieces of the file that they already have to other leechers.
Connectibility: There should be a little circle at the bottom of your uTorrent window. If it's green, it means that everything is all right and you don't have to do anything. If this is yellow, it means that your client is not accepting any incoming connections. This means that you can still download, but only if your client is the one that initiates the request. In other words, you will not get any remote connections. If it's yellow or red, then you should open the port that you use for uTorrent in your firewall and router. You can find a guide for just about every firewall and router in the world at http://portforward.com This site will tell you exactly how to get yourself connectible so that you can get the best speeds possible.
Seeding: Once you have completed your download, you are no longer considered a leecher. You're now a seeder. `Seeding` is simply the act of uploading the complete file to others. Your client will do this automatically and indefinitely. It will only stop seeding if you stop the torrent. It is considered impolite not to seed back at least the same amount that you have downloaded.
Please note that this is a very barebones explanation. It would behoove you to look up the information that I have left out here for the sake of brevity, if you wish to gain a better understanding of how the protocol works.