If you're using uTorrent, then when you first run it, a "Speed Guide" should pop up. If it isn't the first time you run uTorrent, or it just hasn't shown up, then click "Options" then "Speed Guide" or just press "Ctrl - G" when you have uTorrent on your screen. Click the button that says "Run speed test at: www.dslreports.com" and test your speed. Then when you have your upload and download speed, go back to uTorrent, click on the drop down box that says "(Current settings)", next to "Connection type:" and select the speed that matches or comes closest to matching your upload speed.
well there really isnt much of a diffrence, but you want down to be unlimited and up to be somewhere around 20kbps for your internet speed, you should have best luck right around there, but i may be wrong test diffrent up speeds but 20 should be about your sweet spot