In French language, there are some accents and letters that are not easily accessible from standard QWERTY keyboard, yet adding French keyboard layout means using AZERTY keyboard layout!
Easy way to access those letters while still using QWERTY keyboard layout is to use US-International keyboard layout.
The second part of the table in http://www.forlang.wsu.edu/help/keyboards1.asp shows how to easily type çàéëê and others using combination of “ , ’, ^ and ` + aiueoc in US-International keyboard (qwerty)..
the character € and æ still need alt-keys combination: alt+5 for € and alt+z for æ.
Instruction to install US-International keyboard can be found at http://www.starr.net/is/type/intlchart.html