First, check the Wiki. It walks through what you need and the differences between different ways to do it:
http://wiki.arcadecontrols.com/wiki/PinballAnd this next part is "borrowed" from another site.

Four components of pinball:
VPinMAME roms
VPinMAME Tables
Visual Pinball Tables (Original & Recreated)
Future Pinball Tables (Origina & Recreated)
VPinMAME roms
This contains the actual roms out of the original pinball machines that are required for the VPinMAME program that emulate those machines.
It also contains rollback roms (to go back to a previous version of the VPinMAME emulator) and other roms (test drivers etc).
VPinMAME Table
Contains the graphical overlays as used by the Visual Pinball program. This program hooks into VPinMAME to give you an accurate simulation of actual pinball tables. If you want to play a table you've seen in real life you need these 2 things and get the Visual Install Pack that contains all the required programs in an easy to use setup.
Visual Pinball Tables (Original & Recreated)
These are the tables for use with the aformentioned Visual Pinball program. The difference is that these do not hook into the VPinMAME emulator, so no roms are involved. The torrent contains 4 sections
Recreated TablesRecreations of other pinball tables, for example, tables from the 50's that didn't use any roms, computer game remakes, tables whose roms are not available yet.
Recreated Tables OtherFlipperless recreations, for example bagatelle tables.
Original TablesBrand new pinball table creations for your gaming pleasure
Original Tables OtherHave a guess! Flipperless original table creations.
Future Pinball Tables (Original & Recreated)
This means tables for use with the new pinball simulator Future Pinball This is a much more modern program, allowing for fancier graphics and much more accurate physics than Visual Pinball - this is reflected in the table size! It is still very much a work in progress, with the original release only being made a couple of months ago so several key features are still missing. It does not hook into VPinMAME but there are still some great playable tables to be had.