LOL - I wouldn't rely on MSFS to tell me where due north was!
Not even roughly!
Nah, seriously, although it might've been pretty accurate once, much of the airways and waypoint data has changed drastically - especially in the UK - and stupidly, MS left no easy way for it to be updated internally.
Use what the real pilots use - the UK Air Information Publication. Check out
http://www.ais.org.uk - you'll need to register, but it's free, and is the official word on UK routings and procedures.
For the rest of Europe, register free with
http://www.ead.eurocontrol.int for the same kind of stuff, in all countries which come under the Eurocontrol umbrella. The PAMS Light system there, although quite complicated to navigate at first, will give you all the SID and STAR charts and standard routes, etc.
For America, see
http://avn.faa.gov/index.asp?xml=naco/online/d_tpp for their online digital Terminal Procedures charts and docs - no need to register with that one.
Of course, if you want paper charts, (which cost), you'll have to try Jeppeson, Aerad or the RAF's Air Information Documents Unit
http://www.aidu.mod.uk, or check out Pooley's famous flight-store at
http://www.pooleys.com - but be prepared to make a dent in your wallet!