Hi all I really need help as this camera lark is a minefield and I'm starting to drive myself nuts !!

I have a beyond gorgeous baby who cries alot, however my wife has been constantly nagging on about taking him to a photographer for some portrait pictures.
A friend of mine suggested that I could achieve equally good results myself if I bought a nice camera and software.
I really like the idea of this and I feel like Ive got an alright eye for taking a nice pic.
Could somebody please please please help me in picking a camera which would take good portrait pictures inside/outoors with a view to be more ambitious and arty too?

Dont want to spend more than £400 really.

Thank you very much in advance.