Start now by getting some cardboard boxes and packing the things you don't use on a daily basis. You can buy boxes or you could just go to your local supermarket and ask if they have any. My local shop always has loads of crisp boxes they give away to people moving. Pack things like crockery, cutlery, pots & pans - just keep out a couple for you to use in the meantime and pack the rest. Same with clothes, keep a few items you will need and pack the rest into suitcases, black bags or boxes.
Do you have anyone to help you move or will you need to hire removals? If if you don't have a great deal of stuff you could just get a 'man with a van' to shift the larger items.
Last time I moved, I had both properties for about 2 weeks so I moved the small boxes myself gradually and then the large stuff (settee, washing machine, fridge, wardrobes etc) went last on my final day in the old house. It was far easier moving stuff bit by bit than having to move everything on the same day!
Thanks beanie We will have lots of help with the big stuff, house is literally opposite us which is good! Poor dd 3.5 has been in our room so I'm very excited that she will have her own room at long last, the house was ideal for me and ds but then later when I met dp and had dd it's so cramped so storing anything to move will be a nightmare. We've got both dc minded tomorrow so are both going to crack on with the bigger jobs ie loft/ cupboard under stairs and have got plenty of black bags.
Dp bringing home lots of boxes from work today and am going to be ruthless as although we're not hoarders by any means, we've got a lot of stuff and I don't want to move with anything that's been forgot about in a cupboard.
I'm hoping we have a few days with keys to both houses, it just seems like such a massive job to do, thanks again for your great advice