Bob's your uncle (sometimes elaborately Robert's your mother's brother) is an expression commonly used mainly in Britain and Commonwealth nations. Typically, someone says it to conclude a set of simple instructions to mean, "And there you have it", or "You're all set". For example, "To make a ham sandwich, just put a piece of ham between two slices of buttered bread, and Bob's your uncle". http://en.wikipedia.org/wiki/Bob%27s_your_uncle

i think they meaning is special for uncle but whats mean the (bob) i dont know

This phrase derives from the slang term 'all is bob', meaning 'all is well'. That term is listed in Captain Francis Grose’s Dictionary of the Vulgar Tongue, 1785: "A shoplifter’s assistant, or one that receives and carries off stolen goods. All is bob; all is safe." Nowadays the idiom means a successful result

It's British. It means "you're all set" or "you're good to go".