Need Root APP and MOD Recomendations

I just rooted my Android phone and I would like to take as much advantage from that as possible. As soon as I rooted my phone I started to play around with overclocking (just for experimentation) and Tasker, but I want to experience much more. I wish to take full advantage of rooting and to learn and experiment with it as much as possible.

Just to add: I intend to spend a lot of time going crazy with this and then use my new knowledge to turn my Android device into a mean productivity, efficiency and portable engineering machine (circuit board readers and editors, source code reviewers, 3D-printer controllers...).