My first 'complex' model. Have some questions.

Here is the blend from my Dropbox. Skeleton Soldier
Should I rig this model before I retopo?
Tips on retopo? (never done it.)
What are some basics I should know going forward?
Thank you for taking the time to have a look and to help.

There are many YouTube retopo tutorial, such as this one:

Should I rig this model before I retopo?

Normally, rigging is done on retopo model.