you have a monitor, right? you'll hear her cry.
as far as cereal goes, just ask your pediatrician. she'll let you know all about what to do. i would just avoid rice cereal and stick with barley because of the arsenic issue. and you'll have your mom for support. you're going to do a great job. and if you make mistakes (which we all will) they won't notice or remember. you'll learn as you go.