Spider-Man comic canon?

I'm not very knowledgeable about Spider-Man comic canon, basically I started reading the current Amazing Spider-Man series because of JMS, and I've also read the earliest Amazing Spider-Man issues #1-43 in TPBs (and intend to buy the other "Essential Spider-Man" collections eventually, unfortunately I just can't buy all comics I want at once *sigh*) because the Spider-Man from back then is just a classic and also lots of fun.

Anyway, I've thought that there are currently two Spider-Man continuities, the regular, and the one from the Ultimate universe. So when I ordered the relaunched "Spectacular Spider-Man" series (written by Paul Jenkins, pencils by Umberto Ramos, inks by Wayne Faucher), I expected it would be in the regular continuity, as it's not advertised as an Ultimate title. But I can't make sense of it at all. It seems to feature a younger Peter, but still Aunt May knows he's Spider-Man, and it refers to past events as if it is the continuation of a rather complex earlier backstory. And -- as usual -- I'm just confused.

I mean, the series is now into the third part of a five part story, and I figure I'll get the next two issues at least, because the story is interesting enough, and the art is decent, though a bit too cartoony for my tastes. My best guess is that somehow this series is connected to the "Peter Parker: Spider-Man" series, a continuation, or at least in that universe, that has to be different from the regular Amazing Spider-Man continuity. But I wish they had said so in their catalog ad, because I never followed that series.

I don't know, I guess I need additional footnotes to make sense of this stuff, or a legend, or something.