C.R.
Our church ladies group was kind enough to provide cake and punch for our son's baptism. Afterwards, just the family went out to eat at a local restaurant. If you chose to do something at home, see if family members would mind doing a potluck of sorts but don't feel bad if its just cake and punch.
For the baptism, if it's allowed in your church, see if a relative or friend could video tape the ceremony from off to the side or somewhere out of the way. I know our church did not allow photographs during the ceremony but our pastor did a few posed shots afterwards. Also...CONSIDER THIS...instead of getting a full or long gown with a lot of material, see if you can find a nice little white dress or outfit. Our pastor asked us not to use the frilly or long type (I think he forgot we had a 6 month old boy ) because it's easy to 'lose' where the baby is and they could have a hard time holding on. Just a suggestion, the most important thing is that you enjoy this special day with your family!