I have over a year of professional experience of web and application development in Java using Netbeans IDE... Now for a couple of applications that my company intends to come up with I need to get started with Android Development. And we eventually plan to get into Android and Arduino based applications cum embedded system development.. 

With all these having said I would like to get a word from all you folks on how should I get started with Android development...

What I want to know is

1. Which IDE is better from Android perspective? Netbeans or Eclipse?
2. Are there any frameworks like Struts hibernate and UI development Frameworks like jQuery in Android?
3. we plan to come up with android versions of our existing applications like ERP solutions and other's.. they are built in Java using Struts2 and jQuery.. How should we get started to port them on android?
4. While I started with Android in netbeans it asked me about the version of Android like 3,4.0 and other for which I am developing my application.. So which version of android OS should we think off while getting started with development?

NB: I am a experienced Java developer but an absolute beginner with Android..
post and opinions on how we can start with Android and Arduino are most welcome...