From the estate agent taking it on to their books to getting it on rightmove is not long. I think our estate agent came in the morning and by the afternoon it was on rightmove. Sometimes they put them on without pics etc until they get them.
I am an estate agent but up in Scotland. We usually say 5 working days from being appointed but we have home reports etc to be sorted as well.
At the moment, when people ask me how long properties are taking to sell I am completely honest (I don't work in a big city - think averaged sized town) and say that property is taking a while to sell. You need to think months rather than weeks so if it sells before that then it is a nice surprise. If you are in it for the longhaul then you won't be deflated if you are not under offer within a few weeks.
Don't be greedy. Keep your price down and be prepared to negotiate.