Promerica - Overcoming Objections and Answering Areas of Concern: http://unstoppablecrew.net/files/How%20to%20Handle%20Objecti... (training guide for their sales people. It gives you all the ways to overcome people's objections. These are fairly universal techniques so I just grabbed this version since it had good examples for all of them)
Body Language for Sales Professionals: http://www.selfgrowth.com/articles/kyle.html (A good primer for reading body language. Always helps to give you an edge on matching what someone is saying with their body language)
Cold Calling and Sales Pitches: http://info.4imprint.com/wp-content/uploads/1P-11-0511-June-... (Cold calling sucks, but is a necessary evil in any business trying to gain traction. This PDF recommends using your elevator speech for your cold calls which is spot on. Also, you'd be surprised how good you can get once you overcome your fear on the phone, and are able to talk to people and walk them through your pitch)
I'm a dev who has spent many years closing largish deals, and the best thing I've ever read on the subject is "Spin Selling" by Neil Rackham. The focus is on the difference between closing 6 figure deals vs smaller deals and closing deals within organisations as opposed to selling to individuals. http://www.amazon.com/SPIN-Selling-Neil-Rackham/dp/007051113...
It's also the only sales book I've read that actually measures the results of its advice, which might make it especially relevant to technical people.
Brian Tracy - The 24 Best Closing Techniques: http://media.briantracy.com/downloads/pdf/CloseThatSale.pdf (I used this as a reference for years)
Promerica - Overcoming Objections and Answering Areas of Concern: http://unstoppablecrew.net/files/How%20to%20Handle%20Objecti... (training guide for their sales people. It gives you all the ways to overcome people's objections. These are fairly universal techniques so I just grabbed this version since it had good examples for all of them)
The Art of Negotiation - http://interactive.snm.org/docs/The%20Art%20of%20Negotiation... (You should also know the two types of negotiating - Integrative Negotiation vs. Distributive Bargaining)
The Art of the Deal - Donald Trump: https://www.scribd.com/doc/119362644/Donald-Trump-The-Art-of... (It's an old book, but still relevant to today's entrepreneurs. The only chapter you really need to read is the one on the Elements of the Deal.)
Body Language for Sales Professionals: http://www.selfgrowth.com/articles/kyle.html (A good primer for reading body language. Always helps to give you an edge on matching what someone is saying with their body language)
Cold Calling and Sales Pitches: http://info.4imprint.com/wp-content/uploads/1P-11-0511-June-... (Cold calling sucks, but is a necessary evil in any business trying to gain traction. This PDF recommends using your elevator speech for your cold calls which is spot on. Also, you'd be surprised how good you can get once you overcome your fear on the phone, and are able to talk to people and walk them through your pitch)