Sorry for the slow reply Sokun, for some reason the group digest never
made it to my gmail account.
In scrum the main players are:
The Product Owner - This is the customer or the manager of the
project, they decide what features will be in the system and the
priority of those features
The Team - The developers that will build the features in the product
owners backlog
The Scrum Master - (could be one of the development team) job is
remove all obstacles that may stop the team from working efficiently
and to make sure Scrum is followed (they are not a manager of the
team)
Personally I would start full scrum with only three developers. If I
had two I would do everything in scrum except I wouldn't bother with a
scrum master. I would even follow most of the stuff in scrum if I was
working alone except I would replace the team meeting times with
'reflection' times where I could run things over in my head or the
white board and extract my thoughts that way. Although doing it alone
would probably be difficult if you hadn't got experience of Scrum in a
team environment already.