Update README.md

Author: freeman-lab

README.md

@@ -23,20 +23,37 @@ pip install lightning-python
 ```python
 from lightning import Lightning
 
-lightning = Lightning(host="http://my-lightning-instance.herokuapp.com")
-lightning.create_session("provide an optional session name")
+lgn = Lightning(host="http://my-lightning-instance.herokuapp.com")
 
-lightning.line([1,2,3,4,5,6,7,8,0,-2,2])
+lgn.create_session()
+lgn.create_session("provide an optional session name")
+```
+
+### creating a visualization
+Methods are available for the default visualization types included with Lightning
+```python
+lgn.line([1,2,3,4,5,6,7,8,0,-2,2])
+lgn.scatter([1,2,3],[2,9,4])
+```
 
+### setting options
+Visualizations can be customized through optional parameters
+```python
+lgn.scatter([1,2,3],[2,9,4], label=[1,2,3], size=[5,10,20])
+```
+### using custom plots
+For custom plots not included with the default set, specify by name and provide data as a dictionary
+```python
+lgn.plot(data={"series": [1,2,3]}, type='line')
 ```
 
 ## examples
 
-http://nbviewer.ipython.org/github/lightning-viz/lightning-example-notebooks/tree/master/
+See a collection of [IPython notebooks](http://nbviewer.ipython.org/github/lightning-viz/lightning-example-notebooks/tree/master/).
 
 ## complete documentation
 
-http://lightning-viz.github.io/lightning-python/
+Available [here](http://lightning-viz.github.io/lightning-python/).
 
 ## running tests