@fabr6 : Your ratio measures how much you've downloaded vs. how much you've uploaded. If you download a 1 GB video file and subsequently upload 200 MB of that file to others, your ratio is 0.2 (20%). The goal is to have a ratio of around 1.0 (100%), where you are uploading as much as you download, giving back as much as you take.
You can easily see those numbers at the top of your screen here when you're in the Torrents section. You'll see "UL: xxx.. GB", "DL: xxx.xx GB", and your ratio. You can also see this information by clicking on your user name in the upper right and selecting Details & Stats from the dropdown menu.
The way that torrents work is that as you download pieces of the file, your torrent client shares those pieces with other people, so that you are both downloading and uploading constantly. For a newer file here, you may find that once you've downloaded the whole file, you may already have a pretty healthy ratio, as you've been sharing with others as you go. For an older file, where you're the only one currently downloading it, your ratio at the end of the download will likely be 0.
For a newer file that's fairly active, where people are still downloading it, the best thing to do is just keep the torrent alive in your torrent client until you've given back at least as much as you've taken. Your client should tell you how much you've downloaded, how much you've uploaded, and what your current ratio is for each file in your list. Don't delete the file from the list until you've given back at least as much as you took, even if that means that you have to wait another day or two.
For an older file that nobody is actively downloading, where your ratio is zero and nothing is happening, it's still worth keeping that file alive in your client for a while, since you never know when someone might want it. Personally, I have about 50 such files in my torrent client right now.
The way I handle things is that I keep newer, more active files alive in my torrent client until I've given back at least 150%. That gives me a buffer so that I'm able to download those older files that aren't very active and where I'm not able to upload much, if at all, because nobody else is downloading.
The easiest thing to do to bring your ratio up, other than seeding new content, is to take advantage of the "Freeleech" torrents the site offers. Go to the torrent list, then click the yellow "Show Freeleech torrents" link near the top of your screen. Pick one or more of the recent items in that list to download.
Because they are "freeleech," the amount you download will not count against your ratio. The amount you upload from those torrents, though, will count, so your ratio will improve. If you pick a recent, fairly popular freeleech torrent, you'll find that you can maintain a pretty healthy upload rate, so that your ratio will improve fairly quickly.
Another way to bring your ratio up is to upload new content, where you are the original uploader. Like the freeleech scenario, it's all upload, so it will definitely improve your ratio. The longer you keep the file seeding, the better your ratio will look.
A final way to bring your ratio up is to re-load a torrent file that you had previously downloaded and begin seeding it again. You would load the torrent file into your app and point it at the video that you had previously downloaded. The torrent app will scan the file, figure out that it's all there, and immediately begin making it available for others to download.
I hope this helps.