Make or buy a creative cake. Your baby will love looking at the cake as much as eating it.
If there will be other young kids, keep the party short -- an hour or two is plenty.
If you want to decorate with balloons, opt for the silver helium-filled kind. Latex balloons are a choking hazard to kids under the age of 4.
If you're serving food, do yourself a favor and don't try to make everything. For instance, bake the cake but buy deli sandwiches. Or grill burgers and have a bakery do the cake.
Take pictures of the cake and of Baby in his birthday outfit before the guests arrive.
Don't force Baby to be social. With all the attention, your little one may need to retreat for a bit.
Consider hiring a sitter or asking a young relative to stay with the birthday baby when he needs a break.
Consider doing the fun part the night before. Strip Baby down to a diaper and let him experience his first piece of cake. Then, if he's too thrown off during the party to enjoy the "real" cake, you won't feel disappointed.