refining docker istructions

Author: Leah Wasser

README.md

@@ -47,10 +47,29 @@ to activate it once it's installed.
 
 ## Docker Build
 
+To run a docker container you need to do the following:
+
+1. [Install docker](https://docs.docker.com/install/) and make sure it is running.
+
+2. Build the docker image on your compute locally. Be patient - this will take a bit of time.
 Run the following lines to build the docker image locally:
+
 ```
 cd earth-analytics-binder
 docker build -t earthlab/earth-analytics .
 docker run -it -p 8888:8888 earthlab/earth-analytics
 
 ```
+
+3. Run the image.
+
+To run your earth-analytics image you use the following code:
+
+`docker run -it -p 8888:8888 earthlab/earth-analytics`
+
+NOTE: `earthlab/earth-analytics` is the name of this image as built above. To
+view all images on your computer type
+`docker images -all`
+
+One you run your image, you will be given a URL at the command line. Paste that puppy
+into your browser to run jupyter with the earth analytics environment installed!!