[Nyororin]

I`ll jump in to try and help get this back on track.

The biggest problem you`re going to have with looking things up from manga is that at early levels of Japanese it is going to be very hard for you to tell where a word begins and ends - and to tell what part is modifying it (and how it is modified). You will likely be able to figure out the very basic gist of it, but not a lot more. I don`t believe it will really help you learn anything unless you have a good basic background to link something to. But if you do, reading (be it manga or books) is an excellent way to improve vocabulary and learn new patterns...
The thing is, you just have to get to the level where you can recognize a new pattern when you see one first.

I too agree that language acquisition should be a natural process, much like acquiring your first. However, in order for that to happen - you will need to be in a 24/7 environment with that language lacking access to things in your native language... And you will need interactive guidance. Children acquiring their first language who are never spoken to do not acquire functional language skills - just like you won`t if you don`t have some interaction. In a normal situation this is parents, then friends.

Both of those things are hard to come by if you are not in Japan. That is where textbooks and software comes along - to try and fill the gap that is going to form no matter how hard you try if you`re not in the best environment. Is there crap (like I consider RTK) out there - yes. But there is also a lot of decent stuff which will at the very LEAST help get you to the point that allows you to make the best of the native resources available to you. Infants and toddlers don`t learn the beginnings of language from adult level conversation - they learn it from repetition of simple baby level words, then later simple conversation from a parent. At the very least, you can use a book to fill in that section so that you can begin to parse more difficult stuff.