To sign up for Bluemix for first go to this url http://www.ibm.com/cloud-computing/bluemix/.
Sign up using a email of your choice, and fill inn the necessary information.
After signing up you need to redeem your code.
This can be done folloving this instruction https://developer.ibm.com/students/learn/redeem-promo/
Then you are ready to experiment on your own or try out some of the other recipies on this site.