Since you will be building computers from now on, I recomend getting a 10$ PCI (not -e) video card for testing. Will serve you well in future builds.
What a new idea! Oh wait, it's already been said in this thread. :P
One other thing you can do is look for a store that has a good return policy. Either that or a friend with some old hardware.
All you need is that first "backup" card. After that, each subsequent upgrade will leave you with a hodgepodge of "spare" parts. Vid cards are the fastest to go obsolete, so I can see you either upgrading in teh future, or simply getting a whole new machine and only scavenging the HD and sound from your old....
Anyway, see if you can get a "temporary purchase" (good return policy) on a cheap card and see if that posts. If it doesn't, it is most likely your board. If it does, it is your card. Either way you have an answer!
Oh, a few other things:
An electric screwdriver can be your friend.
Get a small-screw storage container before you end up stepping on the ones that spill out of the bag!
Get a good set of comp tools (I have the small screwdrivers, hex drivers, needlenosed and all the rest from craftsman). They come in handy.
Save your packing boxes for a few weeks after installation (make it easier for RMA, just in case).
Hope all this helps!
And have fun with it! Sometimes building the rig can be as much fun as using it! (So long as it all works!!!)