Normally the future price of a commod would be the price today + the cost of storage, interest etc etc.  If you can actually achieve that, traders will talk about "full contango".  That's when speculators will really buy and warehouse material since they have a risk free bet (buy prompt, hedge way forward and hope something comes along to make the prompt jump up).

WTI goes off the board roughly the 20th of the month prior.  has to do with pipeline scheduling.  NYMEX products go off the board the last biz day of the month.  Both are physical settles so if you go off long, you get oil in tank at the defined terminals, with the expectation of scheduling an immediate lift from the seller or into the pipe if WTI.

Brent is just a cash settle based on journalists' assessments of the market.  Which is one main reason it's a crap contract.  But since physical brent trades in 500 KB lots it's difficult to make a contract with physical settles.