Where to put the code

That is the question I ask all the time while developing in Rails. Should I put the code in the helper or in the model or in the controller itself. I guess I need to find some advance Rails reading material. On that note, Roby on Rails has a collection of links to making the model fat and the controller skinny. Put Your Controller on a Diet already!

After reading those blog posts, I am seeing myself putting some serious time in slim up my controllers. They are a little on the heavy side for sure.