This important process is very important for the students and advisors alike. But advisor should act like a mature and responsible person who, unlike the student, has had much more experience in advising of the completion of dissertation. Te advisor should give special attention to all requests of the student as well as his comments or observations. If an advisor is requested to read the draft of the dissertation, he should read it and evaluate it, providing specific comments to the work submitted.
On another hand a student should prepare thoroughly for each meeting with his advisor (it might advisable to prepare a detailed plan of the meeting as well). One should remember that an advisor can not allocate unlimited period of time to the student, so a student should be succinct and provide his advisor wit as much detailed information as possible. If a student has some proposals to resolve some controversial issues of the dissertation that is being prepared or some new ides on the subject that is being researched, he should prepare them in advance and write them down. It is a prerequisite, because your advisor would more likely provide you with the feedbacks on the particular piece of writing.
How you contact with your advisor.
Usually, it should not be a greet problem, especially in this era of mass communications. Sometimes, it more useful to communicate via email or leave voice messages, however your advisor will be able to indicate the best way of communication with him.
One should not be shy, it is especially important for foreign students, who sometimes experience difficulties with their English, and do not want to sound awkward. One should understand that your communication with your tutor and advisor is one of the most important parts of your dissertation writing process, and one that should be prepared thoroughly in order to make all process successful.