The Registration Convention provides a list of objects in earth orbit. You'd need to use this list to make sure that you aren't going to collide with anything currently in orbit. A Collision On Launch Assessment (COLA) must also be performed prior to launch to make sure you don't hit anything on the way up.
From there, NASA's guidelines on cubesats, requires that cubesat operators produce and obtain approval of an Orbital Debris Assessment Report (ODAR). It is a document that:
assures all
interested parties that your CubeSat won’t pose an unacceptable hazard to other
orbiting spacecraft, will deorbit in a reasonable amount of time, and that no
unacceptably large piece of your CubeSat is going to survive reentry when it deorbits and burns up in the atmosphere.
Some other steps are probably necessary in terms of securing the ability to communicate with your spacecraft. From what I was able to gather, space is fairly self-regulated, though renegade launches do happen.