There are several factors here that I haven't seen anyone else bring up yet, so I'll mention them:

1. Negotions will be very different if you need the job rather than "just looking" - especially if they know it. Try not to let emotions get in the way, but it can be tough.

2. Never "negotiate" salary with a recruiter. They make money when you get an offer. They couldn't care less if you get what you want or if the employer will offer you want you need/want.

3. Recruiters don't give a damn about you and they aren't working "for you". You are a commission. They are no different than a realtor. They want to close the deal as quickly as possible and focus on the next commission.

If your first contact with a potential employer is through a recruiter and money comes up, it's 100% about weeding you out. They don't want to waste time with someone who is going to demand more than the employer is willing to pay.

If you don't need the job, your best bet is to talk to them about lifestyle and comfort level instead of money. Do you want to own your own home? type of community? retirement? kids to put through college? The salary required to meet those requirements will be wildly different based on where the company is located, but no matter what the employer's upper limit is you'll know going into the negotiations (later on) that your needs/wants should be met by whatever the final salary agreed upon is. Do not mention what your current situation is. That's completely irrelevant to the discussion.

If you do need the job, and really don't have time to sit around and wait for the best offer possible to come your way, then just tell the recruiter that you'd rather wait until after you've had a chance to go through some of the interview process before talking about money. If they press the issue, suggest that they tell you what the position pays (usually it's a range) and that you'd like to continue forward with the interview. During the downtime, do your due-diligence on the location, cost of living, etc.

Once you're done with the recruiter and through the interview sufficiently enough to start talking real money, it's important (imo) to not worry about trying to squeeze out every dime possible. You should be going into the interview with a number in mind that allows you - and your family - to be comfortable and happy. However, ...

1. Good companies usually have salary ranges fixed based on "level" or some other factors (senior people make X while newbies make Y). Companies that do this have no problem telling you what that salary range is, because they aren't trying to weezle anyone. You should be able to ask them what those ranges are. You should be able to get a sense of what you could be making in the future (but don't count on it!).

2. Remember that benefits can greatly compensate for salary! If the potential employer has a great health package, covers 90%+ of your health care premiums, matches 401K, offers 5+ week vacation, etc. Those things (to you) may be worth far more than an extra $5,000 / year. Remember to give them an opportunity to sell those to you. On the flip-side, if those benefits aren't there, bring those up as part of your negotiation asking for more.

3. This is my own experience, but don't ever take less salary because the company offers great bonuses. It's much better to make $10K more per year than it is to possibly get a $15K bonus at the end of the year. You can invest salary, bonuses aren't guaranteed, bonuses can be taxed differently based on how they are paid out, etc.

HTH