Problem starting up my Macbook

So, earlier tonight my Macbook froze and I turned it off. When I turned it back on, it wouldn't fully open. It got to the main screen, but the task-bar thingy at the top of the screen is flashing on and off. None of the icons on my desktop are showing up except for one for the hard-drive, I think. When I try to start any program, a dialogue box comes up saying that the program unexpectedly quit. If I click anything besides 'Ignore' the dialogue box just comes up again. I'm not finding any answers via googling and I have no idea what to do to remedy this. Any one know what's happening?