These two links may help with the generalities, but instructor styles can vary a lot within and organization/style.
http://www.shugenkai.com/styles.htm
http://www.aikidojournal.com/article.php?articleID=29
What matters most is what is available to you locally. So all the visiting the dojo advice is best, especially if you have some backround and have an idea of what you are looking for.