Cannot connect Samsung Galaxy S2 to computer in storage mode via USB
I highly recommend checking out QTadb. It is a very useful program with a file manager; you can just drag and drop across. If you have an APK on your local machine, you can install it right in the file manager. Plus there is an ADB shell built in, an app list with back up options, and a ton of other stuff.

I would say this is a must-have for an Android developer. It's just extremely useful.

I hope that helps you out.