When I make a transaction, how is it broadcasted to other clients? It's a really nooby question, and with no doubt asked before, but if someone could tell me

a)how are other clients found 

b)how is the information send to them

(please explain in a simple way, because I haven't messed with the bitcoin protocol itself)
They're found using a gossip protocol.
Transactions are sent using this structure: https://en.bitcoin.it/wiki/Transactions