2000 Honda CRV - Check Engine Light

I have a 2000 Honda CRV with about 110,000 miles on it. In August, it leaked some kind of fluid at random - the fluid is dark in color (on the ground) and seems to be oily in texture. This stopped after about 4 or 5 times. On Monday, September 8, I noticed that the Yellow Check Engine light turned on. It stayed on until September 9, and then turned itself off. I was very relieved but noticed that it turned on again yesterday! (September 12, 2008).

I know NOTHING about cars, unfortunately. I had had an oil change back in July and someone suggested that I take it back to the shop that changed the oil and ask to check if they had reset the check engine light.

I don't have a lot of money (I am student on financial aid). I am worried that there might be expensive repairs to be made and want to double check potential problems and severity with you kind folks first. Please advice - what could possibly be going on with this car? Is this going to be a serious issue and if yes, how much should I expect to pay at most?

As far as I know, the car has only been received regular oil changes, never been in any accident, and did not receive a 100,000 mile check with the dealer. Thank you very much for any help you can give me.

What happend, did you find a resolution?
laloquera