Being mostly self-taught freestyle developer and having no experience of working in teams of professionals in serious software companies, having only a very general idea of how the software development is should really be done, I think I've came to a point, when I begin struggling from lack of order in my work. I think I should get acquainted with professional software development technologies to optimize my own productivity and to extend my choice of work by increasing capabilities to work in teams and bigger companies.

What should I begin with? Of course I am googling on this subject right now, but maybe hou have some real experience based recommendations to share?