My experience with comics has been that the best thing to do really is to just jump into whatever you want to read. I started out with Hell Boy because I was afraid of dealing with continuity. But I've become an avid DC reader, and while I can't talk about Marvel, I can tell you that it's pretty hard to go wrong with DC stuff.
If you really enjoy the continuity stuff, you might actually find Flashpoint (which has now been collected in trade) to be a really good jumping on point. You won't need any real knowledge of what happened before to understand what's going on, it's a really awesome read, and it'll finish by dropping you right into the New 52 universe.
After that, all of the New 52 series have one worth of trades, so you could pick a hero you're interested in, and grab the first trade, then catch up on the remaining issues.
Wonder Woman (who you mentioned liking) isn't bad at all, and there are some really good Batman series (there are now, I believe, five Batman titles running right now [and that's not even counting other members of the "bat family"]) Plain old vanilla Batman is really good, the Court of Owls storyline it's been working through is really really good, and even contained one of the best issues of any comic I've ever read. I'm not going to give it away, but I will say that by the time you're done spinning the comic in every direction imaginable your mind will be as blown as it possibly can be. Batman: The Dark Knight and Batman and Robin are also quite good. Batman and Robin in particular is quite interesting just because Damian makes for a really interesting Robin. I would avoid Batman: Detective Comics though, which hasn't been quite as good, and while I like Batman Incorporated, if you do decide to read it you should keep in mind that even if you have read all of the parts that came before it's still nonsensical.
The other Bat family title that's really really good is Batgirl. Trust me on this one, it's a choice that would be impossible to regret.
I would also suggest Red Lanterns, which has been awesome, Green Lantern (written by Geoff Johns), or Green Lantern: New Guardians (which incorporates members from every color of Lantern corps). Aquaman (again written by Johns) is also awesome. And if you've got a taste for the metaphysical, Captain Atom is really good.
Of course there are a ton of other good series as well. I don't read them all, but I read way more than I ought to, so if you've got a question about a particular series, ask away, I read about half of them, so there's a 50-50 shot I can give you an answer.
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