Interviews usually take 30 minutes to an hour. There is no specific structure. The best thing to do is to present yourself as honestly as possible and not to 'oversell' or 'undersell' your skills. Be polite and try to be calm.
Employers want to discover who you are during the interview. Do not be surprised if they ask questions about your personal life. Non-professional items usually take up a small part of the interview and are used simply to make the atmosphere more relaxed. The employer should already know basic things about your experience from your CV. Use this opportunity to speak in greater depth about your skills and why you are the best candidate. Also, try to convince them that you will contribute something that will enhance the quality of their company and that you are willing to work hard to do this.
Any questions from you regarding the nature of the job are appreciated, but it is better to wait until you know for sure that you have got the job before asking about the salary, unless the employer brings it up first.
At the end of an interview, the employer usually tells you when you can expect to hear from them again. If they do not, the odds are that they are not interested. If the employer has not contacted you within the period you were told, the best thing is to simply contact them and ask for feedback.
While you will always present yourself better in person, if you cannot attend the interview, check if the employer can conduct the interview as a conference call. Video-conferencing is also growing in popularity in Iceland.