the terminology is foreign to me ...

can anyone help a gal out? I know how to download a torrent; I know how seeding happens (KINDA ...) what I know is that when I'm done downloading fully, then I'm seeding (don't understand the mechanics and the tracker thing)...but what I'm curious about ... is how to edit trackers, how to add a tracker, why would I do that? and MOST importantly how can I speed up my downloads?