Lucky you 
- My lovely sister gave me a Dolls house kit to build for my birthday a couple of months ago (we'd had a conversation months previously about 'the toy I always wanted but never had' 
)
Anyway - any of the online Dollshouse companies will sell the bits and bobs you need like hinges screws etc. But also worth looking to see if there are any independent shops in your area, as I find they are often cheaper.
I have also been getting a dolls house magazine every so often - for idea of things to make, and I borrow books from the library on how to make furniture etc.
Another thing I've just found is a Dollshousing group that meet locally to me - which I am going to join, - there might be one near you and I reckon there will be lots of people to give you ideas (that's what I'm hoping anyway)
You can download thing from the internet too (google Doll house downloads) and there will be stuff to make miniature newspapers, food wrappings books etc etc.
I've got a catalogue from Dollshouse Emporium which I am just using for ideas rather than actually buying anything, - I thought I would copy some of the little bits and pieces in Fimo etc.
For decor in mine I used rolls of very small pattern wallpaper from B and Q (cheaper than the special DHouse wallpaper), fabric scraps with a carpetty texture for carpets (e.g.needlecord), and sample pots of paint for paintwork.
let us know how you get on - I'm a total beginner too but am absolutely loving this project, and would love to share steal ideas