First nugget of wisdom. It's hard to win at the salary game if you make the first offer unless you guess people's ages and weights for a living - picking the perfect number out of a hat on your first draw is next to impossible. While in some cases it may be unavoidable, shy away from hard numbers. Stick to the position that salary is mere compensation and thusly negotiable, as opposed to the opportunity to work with Company X.
If asked early on, you may want to reverse it on your interviewer(s) and ask, "What would a person with my background and qualifications typically earn in this position with your company?" If asked late in the interview, offer, "I am ready to consider your very best offer." Being asked mid-interview or in an offhand manner is a toughie. Stay with your 'negotiable' position, but the key to making this type of answer stick is to be polite, firm and hopefully final. "I expect a salary in line with my skills and abilities, but what is most important is the opportunity to work for you and your company. I am confident that your offer will be competitive."
Question - when *is* it time to negotiate? Answer - When you have a formal offer in hand. In most cases, the position and opportunity are important over all else; brass tacks like compensation can wait. In your favour, this helps lock you into the position before salary is finalized.
Second nugget. If you can't get away from giving up a number, know that giving a salary range (eg. $60K - $65K) is next to asking for the minimum of the range you specified (eg. $60K from our previous example.) If in your eyes you'll be staying at your present level or moving up, give yourself a modest raise. After all, you're not getting any younger - not to mention you'll now have a tiny bit of space to maneuver should they choose to try and bargain you down.
Remember. Take into account things outside of simple monetary compensation. What benefits does the company offer? Options in company stock? On-job or paid-for training?
It's not in your interest to list pay levels from your previous places of employment. We'll go as far as to say being asked for such is far from being in good taste - but that's immaterial.