Hi Hocuspocus
Thought it might be worth clarifying some of the points made so far with respect to what you might and might not expect from a clinical psychologist (i am one!). Unfortunatly it can be somewhat confusing as there is quite a lot of variation in practice within the profession, so i can only give you some general ideas.
The benefits of seeing one is that most child psychologists can and do work in a variety of ways depending on the 'problem'. So, as others have said, sometimes they provide very limited input other than to provide families with the space to re-evaluate their own situation, maybe with a few ideas thrown in. At other times it is about providing much more concrete help with regard to implementing strategies and evaluating if they are working. And sometimes it is about looking at the wider picture and helping to identify whether there are other difficulties within a family that are impacting on a child's behaviour and thinking about how these might be changed.
As a psychologist i try to work in collaboration with families, rather than as an 'expert'. There are times when some technical know how is useful however, so i may on occasions give 'advice'. The effectiveness of using rewards (like sticker charts), for example, is based on lots of factors. A few tweaks here and there can (sometimes!) make all the difference.
I can't for one minute promise that all other child psychologists have the same approach. However, most work with children in this area tends to be extremly practical. You may go over some of the same ground (such as the charts), as this tends to provide incredibly useful information about what to try next.
With regards to school records, you would need to discuss this at an initial appointment, however any information shared with school could only be done so with your consent. Therefore if you did not give this, information would not be passed to school. (There are some exceptions to this, but they relate to child protection concerns). Recordings of the appointments would form part of your sons's health service records. You can ask for details of the health trusts record keeping policy with regards to what might happen to the information, but in essence it is as confidential as talking to your GP etc.
A magic wand remains an elusive tool which we would all like to offer. In reality, finding solutions can be a slow and painful process, and sometimes we aren't the right people to help, or it isn't the right time or the 'problem' simply disappears of its own accord.
Hmm, anyway think am waffling. Sorry. In summary, yes, it might be useful to ask to see a child psychologist, but they are certainly not the only source of possible help. Might be worth a chat to with ds's GP to see whats available locally. Also might be worth exploring whether there are any 'Webster Stratton' parenting courses run in your area (sometimes run by psychologists, but not always), which some parents I have talked to have rated quite highly. They are very much aimed at the difficulties you have described and are very practical.
Nannyme - I appreciate that you might not have benefitted from your contact with a psychologist in the past. However I think its important to emphasise that adult and child work is very different. I certainly would not consider the work i do with children to resememble a 'shrink' in any way.
Sorry hocuspocus, very long and not too coherant rant. Thats what 4 months on mat leave and a baby has done to meHope its a bit helpful at least .And best of luck!