What is your process for 3d character development?

Alright so im getting into character development what i know so far is that you have to make high poly,convert to low,baking/norm mapping,texture.
Questions are 1) I have a high poly mesh ready to be converted to low poly but is there any free program for retopology.
2) What is your method or process to creating in game characters such as programs you use,methods, etc