If you're going from 9's to 11's, you'll need little adjustments in bridge height intonation and the truss rod, (as long as your guitar is perfectly set up now) but nothing major.
Read up how to do these, there must be thousands upon thousands of internet pages detailing exactly how to go about these, and you'll save yourself a packet.
I'm 28 next month, been playing for like 14 odd years, and if i had paid someone everytime i wanted strings changed and my guitars setup and such, i reckon i would have handed over the price of a brand new AVRI Jaguar and more.
