Don't flame me if I am being sarcastic , but you could at least get a basic idea through Googling rather than whining here !

So you plan to do DDOS ? - You'll be to be precise on what OS does the client use and the server. If Windows , are the service packs installed and which version of Windows. You'll have to set up some basic stuff , on how secure is it or not. Otherwise I'll just assume its a poorly configured server

My 2 cents

To answer your questions , just search the forum or Google it up. Its pretty simple.
No , I am not going to spoon feed you with the information. Its here in the forum itself and you do get a clue of what is WEP and WPA from this thread

3) Its not easy to crack , you must have the knowledge to use it and not to mention the right equipments as well