Hi,
It's potentially quite a big topic, and could require quite a long answer.
Of course the really short answer would be "books and google", but that might not be what you're after. :-)
1) Java.
There are plenty of good books. And quite a few free ones.
One that comes to mind is Thinking In Java. It's free, and available from a number of sites. One of which is:
Thinking In Java Tutorial Programming Java Free eBook PDF File Download
It's definitely possible to get going with little experience. After all we all have to start somewhere! You've already got some small apps working, and that's a good starting place to build on.
Although Android might not be the easiest thing to start with, it'll be more interesting than writing simpler console apps. But you might want to move away from Android and try things out with simple command line programs now and again. For example, it'll be easier to try out file i/o and object oriented ideas in isolation without having to worry about Android stuff. So if you get stuck with something, and it's generic Java and not Android specific, the best approach would be to work on it separately, away from Android. It's easier to get something to work in 5 lines of code than as part of a bigger Android app. And if you're still stuck you'll have a small example you can post on a forum, which will make it easier for people to help you.
2) Eclipse & the SDK
As you've already got stuff working, you're already doing pretty well.
There can be a lot to learn about Eclipse, and the SDK, and it can seem intimidating at first. But you can learn as you go along.
There's an Eclipse tutorial here:
https://eclipse-tutorial.dev.java.net/
And Google provide tutorials for the SDK, which you'll already have seen:
The Developer's Guide | Android Developers
I've written a few Android apps, but I've probably only looked at a tiny percentage of the SDK. Rather than try to learn it all, I just focus on small bits as I need them. That way I'll be interested, and will learn quicker as I'll be applying what I learn straight away.
3) More to know about creating basic apps?
Almost definitely! But I can't tell you what that is. There's lots more that I need to know too, but I'll get there eventually.
You've got an app in Eclipse and can build and run it. There will be more to learn as you test on multiple devices, and release to the market place. But it's pretty straightforward.
The best approach is to ask questions as you go.
If there's an app you want to write, and are enthusiastic, the rest will come easily enough.
I hope that helps.
Regards,
Mark