Updating README with instructions

Although incomplete, this addresses parts of #16

README.md

@@ -1,10 +1,53 @@
 # Installation via git
 
-	git clone http://github.com/rchavik/Assets Plugin/Assets
-	( cd Assets && git submodule update --init )
+	cd $APP
+
+	git clone http://github.com/rchavik/AdminExtras View/Themed/AdminExtras
+
+	git clone http://github.com/CakeDC/Imagine Plugin/Imagine
+	( cd Plugin/Imagine && git submodule update --init --recursive )
+
+	git clone http://github.com/xintesa/Assets Plugin/Assets
+	( cd Plugin/Assets && git submodule update --init --recursive )
+
+	Console/cake settings.settings write Site.admin_theme AdminExtras
 	Console/cake ext activate plugin Assets
 
+## Usage
+
+Once activated successfully, three new buttons (Reload, Browse, and Upload)
+and a new "Assets" tab will be added to the `edit` action of the following
+pages: Nodes, Blocks, and Types.
+
+Clicking on the "Upload" button will bring up a popup window, where you can
+select and upload the asset file.
+
+### Featured Image
+
+When ticking the "Featured Image" checkbox, the asset will be automatically
+grouped under the "Featured Image" record.
+
+A simple helper method (AssetsImageHelper::featured) is included for basic
+markup generation.
+
+### Adapter
+
+Two adapters are provided in the plugin:
+
+	* Local Attachment
+
+	  Default storage adapter.  When using this adapter, assets will be
+	  stored under `APP/webroot/assets` directory.
+
+	* Local Attachment (Legacy)
+
+	  This adapters mimics the original Croogo behavior, where images are
+	  stored under `APP/webroot/uploads` directory.
+
 # Dependencies
 
-- [Gaufrette](https://github.com/Knplabs/Gaufrette)
+- [Imagine](https://github.com/CakeDC/Imagine) plugin which is a CakePHP
+  friendly wrapper for [Imagine image processing library](http://imagine.readthedocs.org/).
+  Tested with 1.0.1-3-g500a559
+- [Gaufrette](https://github.com/Knplabs/Gaufrette) library
 - [AdminExtras](http://github.com/rchavik/AdminExtras) theme