Phone calls within Estonia: you do not need to use the Estonian country code (+372), but only the local 7-digit telephone number or mobile number.
International long distance calls: dial 00 + country code + area code and local number.
Calling Estonia from abroad: dial whatever you need to get an international line in your home country (e.g. 00), then 372 (Estonia’s country code), and then the local number.
There are several mobile communication operators in Estonia offering many different price packages (see below). The easiest option is to use a prepaid SIM card (the initial credit may vary between companies), as in this case you do not need a contract. You can buy these cards from shops and kiosks.
If you have your own phone and you sign a contract with a local company, you should know that calls are billed on a monthly cycle. For example, your phone bill for January is delivered in mid-February.