I don't think super system is relevant for how much the game has changed since the publication of those books. Population tendencies and strategies have changed a lot since the days of super system and harrington on holdem. I would recommend a subscription to a training/learning site. There's some cheap one, midrange and expensive ones online now.
I previously used: Red Chip Poker
I currently use: Raise Your Edge and Tournament Poker Edge as well as reading Michael Acevedo's Modern Poker Theory.
For a lot of these things to make sense you're definitely going to want poker tracker or holdem manager, equilabs (there's a free version), if you're willing to invest money flopzilla or PIOsolver and if you're looking at ICM spots you'll need ICMizer. Not required by any means but they help so you understand the concepts when you can run calculations and find optimal spots. If you're learning poker, I'd get something more recent and relevant than Super System.
