I've been reading it since Battle for the Cowl. Some really interesting and bold concepts, but for the most part the execution has been mediocre. That is until David Hine took over, and now the book is definitely improving. A lot of fans recommend jumping on issue 10, which is the beginning of Hine's run, and you'd only be 4 issues behind, but others complain about not having all the back story to know what's going on from 10 on. There are a few important things in the back issues, but most of it isn't important at all to what's happening now.
i started it from about ish 3 but as the art, and stories got increasingly shittier i had to drop it...im just over all this "ancient secret order" of ppl with "powerful artifacts-to-bequeath-to-a-worthy-successor" bullshit that DC loves to cart out every now and then....heck we just found out that ray palmers uncle is a member of some secret society trying to rule the world from behind the scenes..they even have cool decoder rings and everythning..plus uncle sam and his freedom fighters are dealing with yet another secret society...WTF DC?.....seriously