::Waves to Blu::
Blu's advice is spot-on.
The panel won't ask you much about why you made your initial selection of schools. They will, though, ask you why you think your child needs a place at the school you're appealing for.
You therefore need to make a strong case for why your son needs a place. You can do that by highlighting things that this school offers that would be particularly beneficial for your child, whether that is curriculum, extra curricular activities, pastoral care or whatever. If you are arguing that your child has a social/medical need for a place at the school, back that up with independent confirmation from a professional (paediatrician, GP, educational psychologist, social worker as appropriate).
You also need to do some homework on how many pupils have been admitted in previous years and how many are in each year group now. The school's case against admission is likely to be that they only have (say) 150 places, those places have been allocated and the school is now full. But if you can show that some year groups currently have (say) 142 you can argue that there is some spare capacity and if some year groups have (say) 153 you can argue that the school can cope with going over the 150 figure.
Look too for any errors/omissions/faults in the LEA's original decision - did they measure the distance from home to school correctly? Did they place your son in the correct admissions category etc?
Does your son have a place at any school at the moment? Presumably you were offered a place, even if it wasn't at any of the schools you had chosen - did you accept it?
The panel might well ask if your son has a place for September and it is better to be honest and say that you are appealing at 5 schools. You can then explain that you doing so because you are committed to finding a school place for your son, but school A is the one you really want because it is the one that best suits his needs. If you have rejected a place at the allocated school, you will need to explain why.
As Blu mentions, panels don't like to think that parents are trying to pressurise or blackmail them. The appeal will be decided on its merits. The panel won't reject your appeal just because you have other irons in the fire or because you rejected the offered place (if you did) or took your case to the press, but it's always a good thing to make a positive impression on the panel because - if the arguments for and againt admission are very finely balanced - that could help swing things your way when the final decision is made. I wouldn't say don't show the panel the press article, but do think very carefully about it. If you present it as evidence of how committed you are to securing a good education for your son, it could help you. If it comes across as an attempt to browbeat the LEA or browbeat the panel, it won't. Tread very carefully here.