Photo's a bit dark, but did you plug in power cable(s) in your graphics card? (doesn't seem like it). Also, be sure to put your ram in the right slots, looks like they're in the 2 middle slots on that pic, that can't be right... In both cases it should turn on though.
If it doesn't turn on at all, you should check the power-button cable. Remove it if need be and shortcut the 2 power-pins (Check manual, should be in there) with a screwdriver to turn on the pc.