IMHO the right thing to do is upload at least as much as you download;
if everyone gives more than they get, the total available bandwidth
grows, rather than shrinks.
Ditto.
In all my torrents, I always stop with AT LEAST 1.5. If you need the bandwidth and are running on a normal cable modem with 50 kb/s max, limit the upload speed to 25 kb/s and you'll have enough to surf the web