When will the baby's gifts be opened? This can be at any time during the shower, but as the last activity is generally preferred. If you want to have the guest of honor open her gifts before the food is served, that is fine, too.
Are there any other things that might be forgotten while planning the shower, thus causing stress? Yes, another thing to plan concerns the decorations that you will want to use. Order or buy them enough in advance so that it won't become a last minute stress. Don't forget to have some kind of guestbook available. This is where someone will record which gifts were given by whom, and you may also want to pass it around at the shower. That allows guests to write some words of wisdom for the new parents.
Be sure to get the invitations out in plenty of time. Some hostesses will call guests with a verbal invitation, but it is always a good idea to have the time and date in written form. This does not have to be sent on expensive invitations, even computer generated is fine, but it assures that guests will not forget when and where the shower is being held.
Other things that may be forgotten in the shuffle include making sure you will have enough seating space and chairs available, buying your tableware, plates, and cups early, and deciding whether or not you will be giving party favors.
First and foremost, be sure that you give yourself enough time to plan all this out leisurely and you will assure an enjoyable occasion for both you and the new mother.