Do you have Omni Wheels:
or Mecanum Wheels:
If you have omni wheels you aren't gonna go sideways unless you add something to push you sideways or have them at 45 degrees to each other.
If you have mecanum wheels then this is the simple version:
http://www.superdroidrobots.com/prod...heel-Guide.pdf
And this is the more in depth version:
http://thinktank.wpi.edu/resources/3...canumDrive.pdf
I'm sure there are other FRC specific resources available as well.