Check in your owners manual...or on some vechicled when you pull the fuse door there will be a sticke telling you what fuse your looking for...there will also be a small pair of tweaser type pullers.....should be a piece of cake...probably a 20 amp.
check the fuse and if it is ok then try and hitting the heater motor it is under the right side of the dash, might be a cover. if it starts working after hitting it you need a motor!