It isn't enough to be good looking. You can be the hottest guy in the city, but if the right professionals don't know about you, you will not go anywhere. You need to "network." Networking means simply making contact with others who can help you get to where you want to be.
So, part one of career networking for a male model is meeting and getting to know professionals who are not just willing, but capable of helping your career.
Avoid networking in the wrong place and with the wrong people. Most guys stop networking as soon as some random photographer contacts them. Do not stop your search for more knowledge just because you meet someone who talks a good game, as more people you know in the industry, the better.
Join model networks, discuss your doubts in model forums, look for other models that already have experience and ask them for advice.
Just as any other profession, in modelling who you know might do wonders for you.