Right... What To Expect says:
Tell her what's happening and be positive about it - check
Give her a preview: take her to visit the house if you can but certainly the outside and the local area, esp local shops/park/pool/walks you'd be likely to use a lot.
Share any ambivalent feelings you have about missing your old house so she knows that's normal and ok
Don't throw her things away as part of the move. Wait until she's settled in the new house.
Play moving games with dollies and teddies and cardboard boxes as houses.
Make sure she gets no less attention - big up her trip to nana's, ring/Skype/visit her often while she's there. In fact they suggest shipping her off could be counterproductive depending on her character.
Pack her room last and unpack it first.
Make no other changes, if possible - same toddler groups, nursery, etc if possible, don't start potty training if you haven't already, etc.
Let her explore in her own time.
HTH