Iran currency is the Iranian rial, but 'toman' is more common. Each toman equals 10 rials. All of usual transactions are performed by the toman and the Iranian rial.
Here are some pictures of the banknotes:
Rial equivalent of USD1, €1, and £1 is about 35000, 40000, and 51000 respectively. For approximation of your mind, a Chelo Kabab can cost at least about 200,000 Rials, and 9 grams of saffron cost around 700,000 Rials.
Here is a converter: