We actually don't need a great deal of information to provide an estimate. Obviously the more information that can be provided the better and if you provide a full Icon Design Brief we can give you a very accurate quote from the outset but if you are in a hurry and just want a ball park figure, then the following should be fine.
Any other information is a bonus and if you require a fixed quote, please look at the article on Preparing an Icon Design Brief for the full run down of what we will need.