If you have no power to the board at all there are two possibilities that pop in my mind. First of course is that the powersupply is simply toasted, if you dont have access to a multimeter, you might wanna call a local mom and pops computer shop and ask them if they can check your powersupply for you. (ask if they sell them so they'll have some interest in helping you). One of the nerds in a local Radio Shack might love to pull out the multimeter too. They should be able to tell you what the voltage output is easy enough.
Secondly, and I admit this one is a little weird but its true, I have seen motherboards that use plastic connectors to prevent the board from contacting the case chassis, and I have seen connectors/screws that have to ground the board to the case to complete the circuit, I of course know nothing about your board or powersupply or how its grounded, just something to check if you've done everything else.