Two books have been influential in teaching me networking skills. The first was one I read when I first went out on my own. This was Swim with the Sharks: Without Being Eaten Alive; Outsell, Outmanage, Outmotivate and Outnegotiate Your Competition. Mackay also wrote Dig Your Well Before You're Thirsty: The Only Networking Book You'll Ever Need
. Both are excellent books for learning networking skills. More recently Keith Ferrazzi wrote Never Eat Alone: And Other Secrets to Success, One Relationship at a Time and 
Who's Got Your Back: The Breakthrough Program to Build Deep, Trusting Relationships That Create Success--and Won't Let You Fail. Both excellent resources as well. If you had to pick one I would most likely follow Ferrazzi in Never Eat Alone.
