Develop Reference

Separate Android SDK for Unity project?

I have a Unity project that uses google vr. Unfortunately, there are some incompatibilities with the newer versions of tools and platform tools in the android sdk.
I think I can just have a separate android sdk that has the older, compatible versions of these folders and put it in my Unity project. This would allow me to keep the android sdk associated with my Android Studio projects up-to-date and keep my Unity project working. BUT, it means having two copies of the android sdk... which are big (It said ~30G when I started copying my android sdk).
Is there a more elegant solution that would not take up so much space?

The Android SDK is not particularly large: you can choose which parts of it you need, and install only those.
One of the things that make it so large is Android device images (emulators). If you don't need those, don't install them and it should take less space on your hard drive.

what u need to do is to specify android sdk in Edit-Preferences-External Tools

Android development setup on Windows

I have php and .net programming experience.
I want to set up a development system on a windows 7 64 bit PC. I could do with database usage at a later date. I want to do it as hard coding not use software that you just drag and drop objects to play games.
I have already downloaded and installed jdk-8u20-windows-x64.exe
What do I need to do next and in what if any order.

Get your Android SDK and Eclipse IDE here
https://developer.android.com/sdk/index.html
As this is not a programming question please use Google Search or a source specific to your problem next time.

It's quite simple really. I would suggest using Android Studio, which can be found here :
Download Android Studio
It says it's a beta version but I have (and I'm not the only one) been using it for production without issues for months now. It's really a question of preference but as far as I'm concerned, I found my productivity to be much higher on Android Studio than it was using Eclipse.
Once it is installed, find the SDK manager and download the latest SDK version, build tools and other things you may need (such as the USB driver for debugging, the support library, ...) :
I highly recommend you go through the training on the official documentation page to start getting used to your new toys :-)

Can You Set Up Android Studio/SDK Manager to check for/get the latest rev of AWS SDK for Android?

So I'm going to start experimenting with AWS SDK for Android from Amazon and while I imagine it's quite stable and bug free by this point, I want to setup my environment (Android Studio) to check for the latest version of AWS SDK for Android just in case there are package updates while developing. I looked around on the AWS SDK for Android SDK getting started page and there doesn't seem to be anything about this described, even for working in Eclipse which I know should support this kind of functionality.
Is it even possible with Android Studio and the SDK Manager to be setup such that it checks for the latest packages of the AWS SDK, does Amazon host their SDK for Android somewhere it's pullable from in such a fashion, and if so, how do I do it?

So really your best bet here is to pick the current SDK build and stick with it. You aren't exactly sure what they might change, and it might have unexpected issues in your code. Even when you use a dependency management like Maven, you rarely change the version of your dependencies.
But, if you want to stay up to date, your best bet is to check it out from their GIT repo, and stay current that way.
https://github.com/aws/aws-sdk-android
It provides you a link to this repo here...
http://aws.amazon.com/sdkforandroid/

What Version of Eclipse do I use for Android?

I am sure this has been asked before, but I can not find a good answer. I want to create an Android app, I want to use Eclipse, but there are so many versions on the downloads page, and I am not sure which one I should use ... some of these include
>Eclipse IDE for Java EE Developers
>Eclipse Classic 4.2.2
>Eclipse IDE for Java Developers
>Eclipse IDE for C/C++ Developers
>Eclipse for Mobile Developers
Thank You :)

I would recommend the ADT Bundle, as it has a suitable version of Eclipse, plus the necessary Android plumbing, in one download.

The answer depends on what you want to use in Eclipse. If you are just starting in the Eclipse world go for the smallest (lightweight) packages because they will also make your Eclipse experience smoother (loading, UI, etc.). From your list above I would choose Classic, but, if you ONLY want to focus on Android development, you could try the Google prepackaged version of Eclipse (ADT, see below).
You can install either:
standalone Eclipse plus the ADT plugins or
the prepackaged version of Eclipse with ADT provided by Google (recommended)
If you already have an Eclipse installed (which you probably want if you already use Eclipse and want to keep the existing worspaces/preferences/etc.) you can only install the ADT plugins from here. And both Indigo and Juno versions of Eclipse should work. Of course that you should try and upgrade your workspace first to Juno and than install the ADT plugins to avoid any other surprises.
The Google prepackaged version of Eclipse is here and will give you less headaches because you have almost everything into it. You only have to use the prepackaged download manager inside Eclipse to download platform versions and device images (and many other tools and examples). This will use Eclipse Juno version.

I would recommend the classic version, but in my opinion intelliJ is better
http://www.jetbrains.com/idea/
Google has just announced at Google I/O a new IDE called "Android Studio" which
is based on IntelliJ and can be found here:
http://developer.android.com/sdk/installing/studio.html

Any will do, but the most recommended one is Mobile. Also check the new IDE that Google released just for that (Android Studio).

Download Eclipse Installer from https://www.eclipse.org/ (top right
corner)
After downloading start installer.
Check if there is an option as "for Android Developers". If there is
not, click the updates button on top right corner. It downloads
updates for installer. After the download is completed check again
the list.
Download Eclipse for Android Developers.

For android development, should I upgrade to Eclipse v4 ?

I'm using Eclipse v 3.7.2 to develop Android apps. I've been at it a few months and making some decent headway and am not sure I want to rebuild my development environment.
I don't doubt that Eclipse has been improved, but has it been improved for android development?
Before I rebuild my environment I'd like to know why should I fix it.
Can any one tell me if they have found any major feature advantages to upgrading to version 4 of eclipse?
I tried posting in the android enthusiasts group to find the question was "off topic", as there are many developers here I hope ye don't mind a non coding related question.

There is absolutely no need to rebuild anything. From your 3.7.2 installation you should be able to update your installation to 3.8 in place. Use Help->Check for updates with the 3.8 specific update site: http://download.eclipse.org/eclipse/updates/3.8
That way you get all the bug fixes and changes of the last release cycle, but do not need to switch to the e4 version of Juno. For you as Eclipse user the changes in the modeled workbench and CCS styling are not really important.
Note: Updating in place might be a problem if you use Linux and have installed Eclipse via a repository manager.