Oxtail soup in itself is very nutritious, very delicious, and can be made in mass quantities, so a round of applause for your choice. When my mother makes this soup, she usually adds potatoes, corn, Chinese green vegetables, tomatoes, etc.. to make it have a really healthy and well rounded effect. Those take care of any salad ideas or anything. You can use canned or frozen if there is not enough time, because the stew will take care of it.

When serving the soup, to make your life easier, first ladle the soup for the guests into their individual bowls. Then, have the whole pot there for anyone interested in seconds. That way, you won't have to keep running to fill bowls, and you can focus on being a relaxed hostess (in a way).

I think the perfect dessert with this hearty soup is just plain summer fruits, such as berries, watermelon, grapes, etc... The meat and soup are rich, so a light dessert afterward is most appealing. Also, this way, all you have to do is have the kids help you wash the fruit while you tend to the soup. (I'm not sure how old your kids are, but hopefully they are old enough to do that at least.) Make it a fun family thing for them as long as it isn't more work for you. Also, the fruit can be left on the side with maybe some cream you bought at the store of something. You can keep that in a cooler that is available to the guests if they would like any.

If this is going to be indoors, just put on some relaxing, conversation music so that you do not have to worry about starting conversations. You can cheat on the starters and take pre-paid quiches, bought at the supermarket, and leave them in one area for the guests to enjoy. Again, if your kids are old enough, have them help you serve the appetizers. Not only will that charm the guest, but that will also lift the burden of super-hostess you will have to be playing.

I'm not sure if my tips can help you, but I hope they do. If you have any questions, or any comments to what I have said, please let me know so I can see if there's any way I could help further!

Good luck, and I know your dinner will be amazing!

-spark