Error installing pg gem in Linux

If installing the pg gem in Linux fails with this error:

checking for pg_config... no

No pg_config... trying anyway. If building fails, please try again with

 --with-pg-config=/path/to/pg_config

checking for libpq-fe.h... no

Can't find the 'libpq-fe.h header

*** extconf.rb failed ***

Could not create Makefile due to some reason, probably lack of

necessary libraries and/or headers.  Check the mkmf.log file for more

details.  You may need configuration options.

...

 An error occured while installing pg (0.13.2), and Bundler cannot continue.

Installing libpq-dev should solve the problem.

 sudo apt-get install libpq-dev  

Installing Rails 3.2 into Linux Mint (and other Linux distributions)

1) Install RVM:

  bash -s stable < <(curl -s https://raw.github.com/wayneeseguin/rvm/master/binscripts/rvm-installer)   

2) Install or update RubyGems:

 gem update --system  

3) Install Rails:

 gem install rails  

That's it! Any problems, let me know below.