Hello JET,
like always in audio, there are no rules, just guidelines that might (or might not) fit the task at hand.
Plugin order and settings will depend a lot on what you want to achieve. The most common thing would be to have a Limiter as the final processor, to avoid any overloads. Other than that, you will most likely need a Master EQ, a Compressor and/or maybe a Multiband Limiter for spectral balance, but you will have to find out yourself which one comes first. - I know that quite a few master-engineers use small amounts of artificial ambience to enhance the imaging of a mix; there were also cases when some distortion (in the sense of Exciter, or even in the sense of satruration effects) helped the mix a lot. - Sorry to be so unspecific, but it's a bit like explaining how to fly an aeroplane in three sentences. ;-)
That said, it is always a good idea to have somebody else doing the master of a mix you did, ideally in a different (properly tuned) acoustic environment. A "second opinion" helps a lot to avoid misbalances due to personal preferences (or acoustic problems). (Mixing is my main professoion since more than two decades now, and I try to avoid mastering my own mixes whenever I can. :-) ...)
... there are many online sources available covering the topic in depth,e.g. http://www.soundonsound.com/sos/aug04/articles/computermastering.htm , http://www.soundonsound.com/sos/feb99/articles/20tips.478.htm , or books like http://bobbyowsinski.com/The_Audio_Mastering_Handook.html.
HTH,