meetup.com is a good place to start.
Set some basic goals for yourself like meet a new person each week. Get some cards.
If you're really starting from zero in terms of networking, go to a meetup and start talking to people, then aim to spend a year practising networking. You'll find out what constitutes quality in terms of networking soon enough.
Also check out Ruben Gamez's course on mixergy.com/premium called "networking for introverts", and his interview is good too.
In fact, just go watch mixergy :)
If you'd like to have a longer discussion about networking feel free to email me iain@workingsoftware.com.au
I used to think networking was for losers, but done right it's surprisingly non-spammy, fulfilling and lucrative!