Update installation docs

docs/topics/install.rst

@@ -3,14 +3,24 @@ Installation
 
 **Prerequisites**: CloudBridge runs on Python 2.7 and higher. Python 3 is recommended.
 
+We highly recommend installing CloudBridge in a
+`virtualenv <http://virtualenv.readthedocs.org/>`_. Creating a new virtualenv
+is simple:
+
+.. code-block:: shell
+
+    pip install virtualenv
+    virtualenv .venv
+    source .venv/bin/activate
+
 Latest release
 --------------
 The latest release of cloudbridge can be installed from PyPI::
 
     pip install cloudbridge
 
-Manual installation
--------------------
+Latest unreleased dev version
+-----------------------------
 The development version of the library can be installed from the
 `Github repo <https://github.com/gvlproject/cloudbridge>`_::
 
@@ -21,9 +31,10 @@ The development version of the library can be installed from the
 Developer installation
 ----------------------
 To install additional libraries required by CloudBridge contributors, such as
-`tox <https://tox.readthedocs.org/en/latest/>`_, run the following command::
+`tox <https://tox.readthedocs.org/en/latest/>`_, clone the source code
+repository and run the following command from the repository root directory::
 
-    pip install cloudbridge[dev]
+    pip install -e .[dev]
 
 ----------