I used to always have problems connecting things with stranded wire, like battery packs, and with too large of wire, like test leads, and with solder lugs, like potentiometers, to my breadboard. Then I put alligator clips onto 22 gauge wire, and it wasn't a problem. All I did was strip about 3 centimeters off of one side of the wire, and 1 centimeter of the other side. I bought a pack of alligator clips from Radioshack, and crimped one onto the 3 centimeter length of bare wire. To make sure they didn't come off, I put a little solder on them as well.
These things are amazingly useful, and I advise you to make some right away.