^^^Good Advice Above... especially the part on international stations... you will have to go to a ticket counter and sometimes be required to pay a tax there before they give you a pass to get through security.
Once in the gate area... make sure you get to the podium and tell them you want to JS when the CSR arrives at the podium (usually 1:45-1:30 out)... once you get the OMC card wait for the pilots to arrive which will be around the 55 minute prior mark... easier to catch them at the gate area then getting down the jet bridge during boarding process. Once you get on the airplane make sure you stop by and see the Purser/FM and introduce yourself (if you don't catch the pilots at the podium then you have to stop in cockpit)... hopefully the Captain talked to him/her by then and tried to grease the skids on a better seat. You will be assigned a seat in Coach... thats how the computer works out assignments... after that its up to the Captain/Purser to decide. As an offline pilot you cannot sit in the cockpit...