This is a great networking tip if you are looking for a job. Professional networking sites like LinkedIn are terrific for assembling contacts but less effective at building real relationships that might lead to a job offer. For that, you need good old-fashioned face time.
Start by searching your online professional network for people who are working in your desired field or have your desired position. They might be second- or third-degree contacts that require an introduction from your first-degree circle. Once you get the introduction, send a pleasant — not pushy — message that you would love to get together and hear their "story." How did they break into the field? What's been their experience on the job? What advice do they have for someone looking to enter the profession?
If you live in the same town, invite them out for coffee or lunch. If you live far away, set up a phone call or video chat. During your meeting, let them share their story. You don't need to ask if they have an open job as this puts them on the spot and defeats the purpose of this informational session. (Besides, if there is an opening, they will most likely bring it up.) End your meeting by asking for names of other people to contact. Follow up with a thank-you note and if appropriate, include your resume and ask your new contact to keep you in mind for open positions.