Emergency. Please Help

My MacBook does not start ... I get only a white-like monitor ... after some minutes a small file icon comes in the center of the monitor, with a big Question Mark in its center that blinks. My MacBook is about 5 years old (all black). And I am running Lion. I think. I recently downloaded the latest operating system (OSX 10) but I don't know the full number.

I have tried re-starting, etc., to no avail. When the problem started I had running at the same time Itunes and Pages (Iworks). The Itunes stopped playing music for a second or two (never happened before), then started up again. Perhaps I was overloading the system with too many programs ? I also had a small external speaker -- it was plugged into the Macbook with a USB cord (for charging the speaker) and from the speaker to the MacBook was a cord put into the sound-output port.

I am in Sri Lanka on a work-holiday (from California) and I really need the MacBook to access email but more imporantly to download photos and burn dvds with my photos.

So I am really stuck ... and I feel like it is an emergency. So any fixes that one can provide would be most grateful !. Many thanks in advance.

Don