Well, about the system, as I've said, you can approach the interfacing issue in several way.
The first one is about the parallel port, with this approach you can drive your hardware directly by the PC program (temperature sensor), about the vibration detection section you've to put a ADC converter and drive this one by the parallel port pin (I think there is lot of infos into the web about e.g. ADC0804 interfacing try to do some Google search with this string "LPT and ADC0804").
With the serial port approach you've to choose a microcontroller with a serial port (obviously
), like the PIC16F876A.
About the microcontroller you've to design a simple protocol, e.g. ASCII based, in order to address what device you've to read and then send back to the PC trough the serial port the information.
Also about the vibration detection section you can use one of the AD converter built-in the microcontroller (up to 10 bits of resolution).
Here some link that might be useful about the parallel port issue:
http://www.thaiio.com/parallelportinfo.html
Also I've did in the past some working code (Visual Basic 6.0) about the parallel port, let me know if this can be useful for you.
Bye
Pow