I've been through two IPOs (one as insider, one as outsider) and watched a friend (co-founder in his company) go through one recently. This was a pretty good summary but didn't capture nearly the level of stress and anxiety involved. ;)
I've been part of taking a number of software companies public and it's always a taxing process because of the amount of work to be done and regulations to be observed. I have massive respect for the executives who can manage this process. The timeline described here seems approximate to what happens, though I imagine it looks and feels slightly differently depending on where you're sitting.