Ruth H gave a good frosting but I wouldn't use margarine - I would substitute butter instead of margarine. I love the Wilton cupcake and more stand - the size I have is for 24 cupcakes. You can buy it at Michael's with a 40% off coupon or Bed, bath and beyond with a 20% coupon.
http://www.foodnetworkstore.com/ProductDetail.aspx?R=5849...
Wilton's also has "First birthday" cupcake liners that are cute.
http://www.shopbakersnook.com/m5_view_item.html?m5:item=4532
Stick some cute little sugary edible decorations or even a non-edible pick or umbrella, in each - those can also be bought at Michaels, and sprinkle some colorful jimmies (sprinkles) on it and it looks so cute! Also, if you are using white or yellow cake, if you put some colorful jimmies in each cupcake batter before they bake, they come out as confetti cupcakes.
You don't have to be a great baker to look like a pro! Good luck!