Good luck with it Sam's mum! I know how hard it is with another child and mine is twice the age of your 2 year old but still comes in just as I'm trying to get Sam to sleep and he's wide awake then!!!!!
I would say that 7 days should be sufficient time to make really good progress with the sleep training as the earlier they start the easier it is. As regards rocking to set the scene, I'm afraid I'm no expert on this at all, but I would say it's OK to do just as part of the wind down routine.
I think the key for the whole thing is to be consistent. I try to stick to my bedtime routine with Sam as much as I possibly can and do things in the same order etc. May sound daft, but I'm sure it helps.
Anyhow, once again, good luck and please keep me posted how it's going - I'll be thinking of you!!!
Ali