I just purchased Thief the Dark Project from my local resale shop. The box was still sealed. This is the first thief game I will be playing.

Are there any updates or patches I need to install to get the game running?

Install the game normally then install TFix to fix issues with modern systems.

Thank you Arkose. The game is now up and running. I haven't had time to start a new game though. I'll post back if I run into any problems.
+ 1 rep for your help.

EDIT: Does the TFix correct the issue with the movies not playing?

Yes, movies and everything.

Awesome. Thanks again.

I finally got around to starting Thief. I'm enjoying it so far. However, I think the movies still aren't playing. Should there be movies in between missions?

yes. try rebooting the pc.

You can also check that you can manually play movies, if you're careful not to play movies from later missions.

From inside the directory where Thief was installed, look for a "MOVIES" folder and try these two movies you should already have seen:
B01.avi is the movie for the practice level.
B02.avi is the movie for Lord Bafford's Manor.

Rebooting the system had no affect. The intro video doesn't play either.
I do have the latest version of the TFIX installed.

EDIT:

I tried running the command regsvr32 ir50_32.dll (it completed successfully) and running the thief executable file as an administrator. I am still unable to view the movies.

EDIT 2: I just checked my movies folder. The only files present are DEATH and SUCCESS. They both play in Windows Media Player.

EDIT 3: The issue has been resolved. I forgot to install the Direct X 9 redistribution from June 2010 before installing TFIX.
I uninstalled Thief, re-installed Thief. Copied over all the videos from the disc, and installed TFIX.

You should be able to find the videos in the movies folder on the CD.