I don't know how getting on to a panel works, but panel's do have to have lay people on them who are involved in adoption - they have an adoptee and an adoptive parent, a medical advisor, an person involved in education, social workers, legal advisor
Your role is not as far as I know different from anyone elses on the panel apart from the minute taker and the chair. You all look over the information given to you and bring in the social workers or adoptive parents involved to ask them questions, and then you consider all the information and make a recommendation. Obviously the legal, educational and medical advisors are especialy looking at those areas, you would be looking more generally. There are 3 kinds of recommendations panel make - whether a child should be adopted, whether a prospective adopter should be approved and whether a particular child should be matched with particular parents.
I remember my panels well! Groups of about 12 people, spent time talking about me, called me in and asked me questions (you are so conscious they are assessing your every word!), sent me out and did the same to my SW... and i waited outside while they did a "raise your hand if Lilka should be approved/should be matched with DD1/DD2/DS"
A bit terrifying really!! I've been to 5 panels and had unanimous 'yes' 3 times, and one or two dissenters the other times. But it was a majority vote so one or two no's is okay.
I do think there can be use for a non-professional eye sometimes, and the different perspectives that 'adoption triad' members might have. An adoptee or an adoptive parent might pick up on something the professionals might not have for instance
On the other hand I'm concerned that some panels have clueless idiots on them who frankly do have anywhere near enough knowledge about modern adoption issues - take this example for instance. I was pretty shocked that they let people with those backward views sit on panels TBH!
So in my very humble opinion if you want to be a panel member you should be well read up on adoption issues! Emotional needs, the effects of choas and neglect/abuse, the needs of modern adoptees, contact issues etc