List of DC Reboot/Retcon Events?

[Fromper]

I'm just returning to comics after an absence of 15+ years, and I'm confused about the current state of DC's comics.

Is there a summary explaining all the reboot/retcon events? I know all about Crisis on Infinite Earths and Zero Hour (and own those comics), but I stopped reading before Infinity Crisis, Flashpoint, 52, etc, so I've heard some names, but I don't really know what they are.

And not just for the DC Universe, but also Vertigo. I remember in the '90s, there was something about the Sandman/Vertigo universe becoming detached from the rest of the DC Universe, and being treated as its own thing. So I wouldn't have expected Vertigo to reboot when the DCU did. Did it? I noticed there's a new Books of Magic series, and I glanced at issue #1 in a local store the other day. It seems to be a direct sequel to the original miniseries, while completely ignoring the two later ongoing series about that character. Are the other new versions of old Vertigo series reboots, also?

Thanks for any information.