Need to reset phone constantly to make Siri work

Hi,
I love my iphone 5 but just days ago I started having some problems with Siri. Every time I use Siri, I have to reset the entire phone before I can use it again. A friend advised me to do a restore via itunes but I've never done it before. Is it too complicated? Do I need to back up my music and photos before I restore the phone?
