sudo apt-get update
sudo apt-get install mongodb-server -y
This will result in you installing a shell and server of version 2.4.10
This method allows your system to receive the latest stable version of MongoDB, but one that is deemed stable by the MongoDB team, not the Debian team. First add their key so your system recognizes mongoDBs signed packages and trusts them.
sudo apt-key adv --keyserver keyserver.ubuntu.com --recv 7F0CEB10
Now add their repository to your sources. If you want to remove this later, just delete the file /etc/apt/sources.list.d/mongodb-org-3.0.list
echo "deb http://repo.mongodb.org/apt/debian wheezy/mongodb-org/3.0 main" | sudo tee /etc/apt/sources.list.d/mongodb-org-3.0.list
Now install the packages
sudo apt-get update
sudo apt-get install mongodb-org -y
This will result in you installing a shell and server of version 3.0.7