And the interfaces would be...?
Voodoo or not, a code is no good without the code book.
Always look for the following:
Case: ATX or Micro-ATX or E-ATX
Motherboard: ATX or Micro-ATX or E-ATX
Micro-ATX works in
Most ATX cases. ATX will
not work in a Micro-ATX case. E-ATX I don't know anything about.
Motherboard
Socket: AM2 or AM2+ or AM2/AM2+ or AM3 or AM2/AM2+/AM3 or LGA 775
CPU
Socket: AM2 or AM2+ or AM2/AM2+ or AM3 or AM2/AM2+/AM3 or LGA 775
AM2 works in AM2+. AM3 works in
most AM2+ boards. LGA 775 Will
Not Work in any AM# Slot, as AM# is AMD and LGA is Intel.
Motherboard
PCI: PCI or PCI-E x1 or PCI-E x16 or PCI-E x16 2.0
Video card
PCI: PCI or PCI-E x1 or PCI-E x16 or PCI-E x16 2.0
Must match, although I know of no PCI-E x1 Cards.
This go in order of least performance to highest. The only "must match" exception is PCI-E x16 and PCI-E x16 2.0, they are compatible with each other,
but a PCI-E x16 2.0 in a PCI-E x16 will not work as well.
Those are the most important to match up, and easiest to mix up.
With Power Supplies make sure you see:500Watt (or greater) with: 20+4 Pin/24Pin - 6 Pin and 6+2 Pin - 4/8 Pin - and a good brand name such as PC Power and Cooling, OCZ or SeaSonic.
Then you get in to things that are less serious if mixed up:
Hard Drive: IDE or SATA (motherboards support both)
DVD: IDE or SATA (Same)