Pointer 1: To install specific version of packages do

# pip install 'numpy==1.5.1'

Pointer 2: To show what files was installed

# pip show --files numpy
---
Name: numpy
Version: 1.8.1
Location: /usr/local/python-2.7.8/lib/python2.7/site-packages
Requires:
Files:
../numpy/__init__.py
.....
.....

Pointer 3: Uninstall a package

# pip uninstall num
Uninstalling SomePackage:

Pointer 4: Upgrade a package:

# pip install --upgrade SomePackage
[...]
Found existing installation: SomePackage 1.0
Uninstalling SomePackage:
Successfully uninstalled SomePackage
Running setup.py install for SomePackage
Successfully installed SomePackage

 Pointer 5: List what packages are outdated:

# pip list --outdated
SomePackage (Current: 1.0 Latest: 2.0)

References:

1. pip 1.5.6 – A tool for installing and managing Python packages
2. pip – installation