Expedition 14 Commander Mike Lopez-Alegria and Flight Engineers Mikhail Tyurin and Thomas Reiter prepared this week for the planned arrival of Space Shuttle Discovery which launches next week. The crew reviewed the STS-116 mission plans, packed equipment to be returned to Earth, and prepared the station's Quest airlock, spacesuits and spacewalking tools. Reiter will be replaced aboard the station by astronaut Sunita Williams, arriving on Discovery.

Source: http://ftp.amsat.org/amsat/archive/sarex/48hour/msg00135.html

HOUSTON - The International Space Station crew have been preparing for the planned arrival next week of the Space Shuttle Discovery on a complex mission to rewire the station's electrical system.Shuttle Discovery is due to launch at 8:35 p.m. CST Thursday, Dec. 7 on mission STS-116. In addition to work that will bring power online at the station from solar arrays delivered to the complex in September, Discovery also will bring a new crew member to the outpost.

Source: http://ftp.amsat.org/amsat/archive/sarex/48hour/msg00134.html

I realise that objects orbit the Earth by falling around the Earth. But what is it that is pushing the ISS to keep it falling around the Earth?
Does it propel itself forward?
What are the engines and how much fuel do they consume?
Anyone got any reliable information?

NASA has set Thursday, December 7, as the launch date for the next space shuttle mission to the International Space Station (ISS). Shuttle Discovery will carry three radio amateurs, one of whom -- US astronaut Sunita Williams, KD5PLB -- will join ISS Expedition 14 in progress.