Networking
The point of most social events are to make contacts with others - specifically, to present yourself in a positive light to colleagues, superiors, industry leaders, and potential clients. You are making yourself known to others who might not otherwise have heard of you, and you should capitalize on such opportunities.
If possible, obtain a list of attendees from the event organizer beforehand to determine which people you want to make a point of meeting. There may be a few people of name you wish to meet, or you may find it useful to make contacts with individuals in specific positions, or in specific companies. The author fails to mention this, but in the present day, there's a lot of information available online, and a name-search on Google can provide a good bit of intel prior to the actual introduction.
On the day of the event, dress professionally and be prepared to hand out business cards (have them in a convenient location) and accept them from others (have a place to put them where they won't get mixed with your own). Eat prior to the event (even if food is being served, you don't want to waste networking time eating). Place you name tag on your right (where it will be in sight of someone while shaking hands).
At the event, make a point of seeming casual and approachable. Scan the room, making a point of making eye contact. Keep your right hand free at all times (especially, don't hold a cold drink in your right hand), and be careful about your alcohol consumption.
It is permissible to "work the room" at these events - that's the entire point of the event. A person who hangs out at the buffet or the bar is generally seen as being disinterested and unprofessional.
Standing is preferred - it gives you the opportunity to move about. The only time you should sit is when engaged in conversation with someone who is seated, and with whom you would like to remain engaged for a while. However, consider whether making a lengthy contact with a few people is worth missing the opportunity to make briefer contacts with a larger number of people.
Also worth mentioning: you'll have better results going it alone rather than hanging around with colleagues - it is easier to approach others, and for others to approach you, as an individual rather than a group.
Always ask permission to exchange business cards: "may I offer you my card" or "may I ask you for your card." Handle the card carefully (it is suggested to place it in a pocket above the waist). If you wish to make notes on it, do not do so in the view of the person.
Networking events are open - you should not be reluctant to approach someone who outranks you. However, do not ask for a business card from a top-level executive - it's a violation of protocols - but it is a very great complement for such a person to request yours.
Making a graceful exit from the event is as important as making a graceful entrance - just as a last impression is as important as the first. If the event is hosted, locate the host and express your thanks before going.
You will see, and be seen by, other attendees even after you've left the killing floor: in the coat-check room, the lobby and hallways, the parking lot, etc. Be on guard until you've left the scene completely. In fact, the author suggests some of the most powerful networking happens after-hours, by chance meetings on the way out of the place.
After the event, take notes on the contacts you've made (importantly, don't do this during the event, in view of the others). The author suggests going through the cards you've collected and making notes on each person, while the memory remains fresh.
There may be need to follow up in further detail after the meting. Your follow-up should be prompt, so that the other party still remembers you, and gets the impression that you feel taht keeping your word to them is important.