I was looking around for formulas sometime back; really can not remember why, perhaps it was for a class I was taking. I put together a diagram with the basic formulas shown below.
There is a link below the image to a downloadable PDF file.
Below is a link to a downloadable PDF version of the above image.
As basic as it is, the diagram helped me to visualize the formulas. Throwing it up on the site here in case it is helpful to someone else.