Make docs more clear [skip ci] [skip appveyor]

README.rst

@@ -11,25 +11,31 @@ OpenCV on wheels
 
 **Unofficial** OpenCV packages for Python.
 
+This repository generates packages which contain pre-compiled OpenCV binary with Python bindings. This enables super fast (usually < 10 seconds) OpenCV installation for Python. 
+
+If you need only OpenCV Python bindings, no separate OpenCV installation is required. 
+
+**IMPORTANT NOTE**
+
+MacOS and Linux wheels have some limitations:
+
+- video related functionality is not supported (not compiled with FFmpeg)
+- for example ``cv.imshow()`` will not work (not compiled with GTK+ 2.x or Carbon support)
+
 Installation and Usage
 ----------------------
 
-To install this package:
+1. If you have previous/other version of OpenCV installed (e.g. cv2 module in the root of Python's site-packages), remove it before installation to avoid conflicts.
+ - To further avoid conflicts and to make development easier, Python's `virtual environments <https://docs.python.org/3/library/venv.html>`__ are highly recommended for development purposes.
+2. Install this package:
 
 ``pip install opencv-python``
 
-To import the package:
+3. Import the package:
 
 ``import cv2``
 
-`OpenCV documentation <http://docs.opencv.org/>`__
-
-IMPORTANT NOTE:
-
-MacOS and Linux wheels have some limitations:
-
-- video related functionality is not supported (not compiled with FFmpeg)
-- for example ``cv.imshow()`` will not work (not compiled with GTK+ 2.x or Carbon support)
+4. Read `OpenCV documentation <http://docs.opencv.org/>`__
 
 Documentation for opencv-python
 -------------------------------
@@ -138,4 +144,4 @@ Currently, builds for following Python versions are provided:
 - 2.7
 - 3.4
 - 3.5
-- 3.6
\ No newline at end of file
+- 3.6