Howdy, ingvarulpre1885!
Simply answering your first question: Listen to anything and everything, especially if it interests you.
Delving deeper into the topic: Not bashing your study style, because we all differ, but you "study by the book and don't listen to any of the 'lectures'..."? That works with some subjects, but in regard to learning languages, I feel that may cause more harm than good, forming bad pronunciations and whatnot. Which brings me to the first question: The Main track for each lesson is great listening practice, in my opinion. But, if you simply can't bother with the breakdown of the 'lectures', then the Dialog Review track is probably your best friend, repeating only the Japanese conversation from the main lesson sans translation. There's also individual sound clips to most vocabulary throughout the site. All great listening tools, which you are already aware. However, for a "longer period of time" of Japanese audio outside of the intended structure of studying a language, your options are varied. Using my myself as an example, I like "cartoons," including Japanese animation. As listening practice, I'm re-watching my collection of DVDs in Japanese without subtitles. Sometimes, I'll go on the youtube and search for Japanese television shows to watch, or bloggers, both native and foreign speakers. Then there are songs from Japan to consider. Again, because the purpose of most of these is not to teach, quite a bit of what is being said is beyond my level of comprehension, but it certainly helps with improving my hearing of the language. So anything can help; it's just that if you have a interest in the material (other than the language of course, i.e. me liking animated shows versus soap-operas/dramas) you're more likely to stick with it.
As for the name of the soap-opera series, sorry, can't help you with that. For other devices, I only have a blackberry phone and use that to listen to some JPod podcasts when away from the house. I imagine you could download some Japanese story books and songs on your iPad for more listening practice, and find their script and lyrics to read along.
In response to the criticism, keep in mind that JPod101 has been around since 2005. Seven years! is quite the accomplishment.
It was recommended that I start with Season 4 of the Beginner Series, but I chose to start with Season 1 because of "behavioural quirks." haha. True, it seems a lot of the early stuff was done by the "seat of their pants" so to speak. And from my understanding, the newer lessons are far more structured than the older ones, which is natural. JPod is still growing and changes are going to be made, some better than others, but this is what I am coming to like about JPod - its flexibility, which is prefect because language is flexible and dynamic. This truly feels like learning from a friend or family instead of studying with a teacher in a classroom(though nothing is wrong with the latter).
Anyway, hope I was able to help you out a little. Congrats on upgrading to Premium, and may it prove worthwhile to you. I just extended my subscription as well. And Happy Holidays to you as well.