At the rate the telesales and telemarketing industry is going, things are looking better despite all the negative connotations that surround cold calling.

For beginners, it will be rough sailing but that will soon change as they gain the skills and confidence to become successful telesales professionals. Following these practical guidelines should help you make a good start.
Prepare. If you are provided with a script, don't read it. Reading will make you sound like a machine; you sound lifeless. Instead, use pointers or bullets to guide you in your sales call. Be the expert that you should be.
Learn all the things you need to know about your product or service. Also, know what your objectives are as a telesales professional and how you can reach your goals.

Rehearse. Your cold calling preparation will be of no use if you don't practice and rehearse your lines. Rehearsing will make you sound confident in your calls and the words will flow out of your mouth naturally.

Ask questions. An effective telesales professional knows what to ask and when to ask questions in order to gain valuable information. Close-ended questions help you take control of the conversation because they provide you with the kind of information that you need to close the deal. Close-ended questions are questions that can be answered with a 'yes', 'no', or a piece of information.

Be professional. Maintain a professional tone of voice throughout the call. Avoid the use of slang words. Also, treat the customer with courtesy and you will gain their respect.

Be likable. It is a well known fact that people tend to buy from people they like. So be likable and it will be easier for you to persuade people to buy from you. Having a likable personality is one great way to effectively deal with people. You don't have to be pretend to be someone else to be likable.
Just be yourself.

Smile! You will be amazed what a smile can do. If smiling to a stranger you meet can break down any barrier between you, smiling while talking on the telephone will disarm any apprehensions prospects may have about you. Though your prospect cannot see you, your smile is evident in your voice.
You'll be surprised at how you'll be able to put people at ease and build rapport just by smiling.

As you can see, the tips above are very simple and practical. They are not meant as a substitute for your lack of experience. They may not win you more sales but one thing is sure - you will gain the favor and goodwill of future customers. That alone can take you a long way for a successful career in telesales!

Source: Heinrich Churchill link