The Voodoo5 5500 is by far the most unusual of all cards. For a start, it has not just one, but two graphics processors. This tries to double the performance of the card.
Even with 2 processors, however, the voodoo5 5500 offers a maximum fill rate that is lower than geforce cards.
The process of installing the card is the same as of installing any other card. But because it has 2 processors it has to draw current from a spare lead from your PC's power supply. If you dont have a spare lead, a splitter cable is provided allowing you to tap into the power connection of an existing drive if required. All this is covered in the cards documentation, as is the driver installation process.