I never could bring myself to suck on the end of the tube since I was almost sure to get a mouthful of aquarium water...(because I'm dense like that apparently...) ;) So I found that you can take a turkey baster and and do the same thing, and you don't get a mouth full of yuck.
Just squeeze the bulb end of the turkey baster so that the air is out, holding it squeezed, attach the end to the end of your tubing, put it into the tank, and then let go of the bulb. The bulb will then fill with air/water and get your suction started. :) You may have to do it a time or two, but it works well for me. :)
Also, you can use airline tubing, or you can go to a hardware or homestore and pick up pool tubing. I have no idea what you do with it for a pool, but it's just thicker/wider diameter airline-type tubing, so you can get more suction going faster. :)
I hope that helps!! :D