A really useful nugget of information is the whole spices to ground spices conversion. How many times have you come across a recipe that asks for a whole spice such as cumin seeds, and all you have in your cupboard is the ground version?
How much do you need? The general rule of thumb is use half the amount of ground spice to whole spice. So 2 teaspoons of whole cumin seeds becomes 1 teaspoon of ground cumin. Do be aware though that whole spices which have been crushed, can colour a dish differently to pre ground ones. Just go canny when you are adding them. You can always add more, but taking some out is not as easy.