Hopefully Easy!

Hey, hows it going?

I think this should be easy enough to do, but I dont know the code and cant find it anywhere, so if anyway can help or point me to a tutorial it will be much appreaciated.

I have large images as button, and I want to have it so when the user brings their mouse over the image, a little information box will appear (similar to an alt in HTML) and will follow the mouse until the user moves their mouse off the image.

Can anyone help?

Thanks
NH