If you have a lawyer let your lawyer advise you about the extent to which you should interact with minor's counsel. Some lawyers will only want you speaking to minor's counsel (except for things like making appointments for the children or providing names and phone numbers) when your own attorney is present. Other lawyers are happy to let you speak openly with minor's counsel. Take your own attorney's advice about this.
Too many parents who believe they have "nothing to hide" speak directly to minor's counsel when they shouldn't, not because there's something to hide, but because they may overwhelm the attorney, use a tone that is off-putting or otherwise do things that harm their own case.
If you don't have an attorney you are in the position of serving as your own attorney. Minor's counsel may speak with you about the case but you will have to make your own decision about the extent to which you will speak with minor's counsel as "the parent."
Do a Little Research
Find out about the role of minor's counsel from your own attorney, from reading Family Code, Sections 3150-3153 and California Rules of Court, Rule 5.240-5.242. Find out about the particular attorney who's been appointed by asking your own attorney, checking out his or her website or even doing a google search.
Assuming you will at some point be speaking with minor's counsel, do ask questions about the attorney's experience in family law and in representing children and definitely about the extent to which he or she wishes parents involved in the work of minor's counsel.
Make the Children Available to their Lawyer
Minor's counsel is appointed to represent the best interests of the children. That may include the children's express wishes. The children (depending on their age) should be able to contact their own attorney at any time and should be afforded privacy to do so. If the children are so young they can't make a phone call by themselves, it's probably best to call to make an appointment for them.
If the attorney asks to speak with or see the children do what you can to be accommodating. If this means shifting around the custody schedule to accommodate a meeting, do that.
Never ask the children about what they said to their attorney or what their attorney said to them. They are entitled to the same attorney-client privilege as an adult. If the attorney needs you to know something the attorney will tell you.
If you have documents, school records, medical records, which the attorney may need to understand the situation, offer to provide them. Don't provide them without your offer being accepted since the attorney may already have some documents (and doesn't need duplicates) and may not want others.
If you have a written summary of events that might help the attorney understand what's been going on before the attorney became involved, offer to provide that through your own lawyer. If your lawyer advises against it, don't send it. If minor's counsel doesn't want it, don't send it. This is not an opportunity to lobby minor's counsel to "your way of thinking." This is an opportunity to present a chronological history of facts to describe what's gone on before.
Do NOT Be Pushy
It's sometimes tempting to think that, since the children have an attorney, if the children's attorney can be made to understand your position, it could be like you have two attorneys (and that this might better persuade the judge to your position.) Avoid that temptation.
If you make information and documentation available you will be perceived as helpful by minor's counsel. If you try to lobby minor's counsel or, worse, try to tell minor's counsel how to do his or her job, you will be perceived as pushy. It would be hard for a minor's counsel who is the subject of what he or she perceives as "pushiness" not to think that this same behavior may be the way you treat your children. This is a balancing you need to do.
...But Don't Be Shy, Either
If minor's counsel is missing critical information, get it to your lawyer to provide it to minor's counsel. If the Court hasn't ordered that minor's counsel file and serve a "Statement of Issues and Contentions," (like a brief outlining the position to be taken on behalf of the children at least 10 days before the hearing) ask your attorney to request one be ordered by the judge. While it means more work for minor's counsel than just showing up and telling the judge his or her position on behalf of the children, it's essential to provide you and the children's other parent information in advance so that you can either agree with it or prepare to refute it with different information.
If You're Having Problems...
Sometimes parents get the sense that the children's attorney doesn't like them. Sometimes it's based on a misunderstanding that can be corrected with better communication. Sometimes it's true and based on real problems between the parent and the children, the parent and minor's counsel or something else.
If you have an attorney, the best way to address the situation is to discuss it with your attorney and see whether the attorney can address it with minor's counsel. If you don't have an attorney and you're concerned that you are having problems with minor's counsel, see whether you can have a conversation with minor's counsel just to address those concerns.
If Minor's Counsel Takes a Position Against You
While an attorney for the children will have a strong voice before the court, that attorney is not the decision-maker, the judge is. If minor's counsel has taken a position contrary to yours (on behalf of the children) it may be that there is a disagreement as to facts, a disagreement as to problems, or a disagreement as to solutions. If the disagreement is as to facts, your job is to present to the judge facts which are different from those relied upon by minor's counsel (which will give the judge a different impression). If the disagreement is as to the existence or non-existence of a problem, have an open mind about why minor's counsel might perceive this in a way differently from you. Be ready to explain (or have your attorney explain) why there is a discrepancy. If there is disagreement as to the solution to an agreed-upon problem, be prepared to show why the solutions you propose work better for the children than those proposed by minor's counsel.