I have been started my adventure down the Xamarin road using Xamarin Forms within Xamarin Studio (v5.2.1) to generate an Android application. One of the initial problems I came across when generating my Hello.Android app was during the build process; I would get the following error:
Java.exe exited with code 1 (MSB6006)
It turns out that you need to allocate an amount of memory to the Java Heap within the Project Options. Under the Build section, select the Android Build option, click on the Advanced tab. The suggested minimum is 512 megabytes (this needs to be entered as 512M), but I gave mine 1 gigabyte (1G).