There are ahadeeth that encourage a person to see his prospective bride.
One person told the prophet :saws: that he got engaged and he asked him if he looked at her. when he answered in the negative, he said, " Go and look at her, for it is more likely to engender love between the two of you." (Ahmad, Dar Qutni, ibn Majah, al-Baihaqi, al-Tabaraani)
"If one of you proposes to a woman and he can see what of her may attract him to marry her, then he should do so." (Abu Dawud, al-Baihaqi)
The purpose of viewing the woman is very specific. it is to help one determine whether or not he would like to marry that woman. the scholars are fairly well agreed taht once the person has made that determination, it is no longer permissible for him to look at that woman. If a man sees a woman and they decide that they want to marry each other, this does not make it allowed for them to continue seeing each other. In fact, the opposite is closer to the truth. Now there is no longer any need for them to see each other. Therefore, they are no longer allowed to see each other. This is because as long as they have not yet got married, they are still strangers to one another and, as such, all of the general laws regarding the relations between the sexes apply to them.
The look is recommended. The purpose of it is to seriously consider if there could be some attraction between the two parties. The look should ONLY be done if the person really believes that there may be a possibility that he is going to marry that woman. if he, in reality, does not have such an intention, or he knows that such a marriage is not going to take place, it becomes forbidden for him to take such a look. The look is not allowed to take place in private, with the two of them alone. The man may look at the woman more than once if he needs to do so. For example, if he did not get a good look at her the first time-which is not unusual in some areas due to the extreme shyness of both parties-or if he saw her but simply cannot make up his mind about her. Sometimes, due to nervousness or other causes, the man forgets what the woman looks like and needs to look at her again before he can make his final decision. So if there is a genuine need for a repeated look, it is allowed.
The majority of scholars state that he may only see her hands and face.
The woman also has a right to see her prospective groom. Indeed some scholars say that it is more important for the woman to see the man because the power of divorce is in the man's hands, and if he is displeased with the attractiveness of his wife, it will be fairly easy for him to get out of the marriage, but not so easy for her. Hence she must be given priority in this matter to ensure that she may lead a happy married life.
From: The Fiqh of Family, Marriage and Divorce by Jamal Zarabozo, Published by the American Open University, 1997