Advice on where to go?

Hello Mothers and maybe fathers of the internet!

I could really use your help! I'm a budding business trying to advertise a Christmas holiday club in Wandsworth borough that specialises with craft based engineering and programming using micro controllers and Art materials to create Christmas spy gadgets, it will be held in a School in Clapham.

I would really appreciate any advise from local mums or even dads as where best to flyer or put up posters, even websites to approach. Any advise will be really useful and greatly appreciated. 

Thanks

Matt

p.s Merry Christmas!