As many people have said before, the presence of a triangle does not necessarily indicate interconnection (someone mentioned LSH/Legionnaires), and interconnection does not necessarily indicate serialization (see Superman in the early days of triangles).
As an example of nonserial interconnectedness, look at the DC One Million issues of Green Lantern, Martian Manhunter, Resurrection Man, and one of the Superman titles (I forget which one). Plots in these four issues are quite connected, and if you want you can follow from GL through MM, Supes, and Resurrection man. But the only comic that requires you to read anything else is GL – it ends on a cliffhanger. So he’s falling to Mars at the start of MM. You don’t need to see how he got there any more than you need to see how Captain Cold got to the Central City bank. So Resurrection Man heads off to Mars at the end of Supes – you only have to read it if you want to, otherwise, you can follow Superman into DC One Million #4, which tells you anything important that you would’ve missed in Resurrection Man. Or if you want to start with RM – you don’t need to know anything from the Superman issue to follow it. The only backstory needed is in the core DC1M books and maybe the JLA issue.
In the back of each issue is a list of all the DC1M issues, *in order* (with details on that week). It’s not on the cover, but it tells you what order to read the issues you picked up. If you like reading stories about green people, and you bought everything at the end of the month (and by some miracle managed to *get* the first week of DC1M that late), you now know to read Green Lantern before you read Martian Manhunter.