The subject of networking is vast and there are many books written about how to do it and where/when to start doing it. Every industry is different; however, they all have common affiliate networks and trade associations, which are great places to start.
Networking is everything. Next to selling (though it is a part of marketing), it is the most important activity you can do in your professional life.
You should always be networking. You should actively network. You should make it something you do as part of your day to day operations. That advice is good for corporate types, unemployed types, and most importantly of course, entrepreneur types.
Networking really is relationship building. I can guarantee that how successful a person is, is directly proportional to the size of his Outlook contact list. Meaning that over time, successful people build relationships with many people.
Timing is critical to networking. When networking, you should be building relationships for the future and not necessarily for some immediate need. It doesn’t happen over night. If you start networking when you find yourself unemployed, you’re too late. It will take time, sometimes years to build the right network for job hopping. However, if you know that you will want to change a job or start a business in a few years time, you should be planting little networking seeds now; so your network will have time to fruit.