All depend of side on what u play, i usually go on bot side of map, because its easier for adc and support to help me
Depends of a champ ,my 2nd role is jungle.. Also depends of situation .. I prefer blue so i can invade enemy red ..but like i said .. depends of situation.
I like to start blue side with almost all champs, if champion is mana hungry it makes your powerfarming easier and if you don't need mana, it delays your redbuff so you can use it more effectively in ganks since you are more usefull on level 3,4,5 than you are on level 2