I assume you are talking about Family Tree Maker 2012. If that is the case, there are a couple of different things you can do. When you click the PERSON tab (not link, but the tab next to the Family tab" and then click on relationships at the top you can click on the spouse (access from the husband's screen) and click on "preferred" and it will come up first each time.
The other thing you can do is on the family screen you click on the spouse icon to the right of the name in the middle of the screen and click "add spouse" to add the second wife and then "set spouse order" to add the spouses.
If you were referring to the Family tree on Ancestry.com you add a second spouse by clicking on the button that says add family member. Putting in a marriage date on Ancestry will put them in the correct order, otherwise they will be ordered by birthdate.
Hope this is helpful.