Pumping - (for dummies)

Kristyn
Hey Everyone,
I hate to sound silly, but I'm just new to this... 
Can anyone explain the process from pumping - freezing - warming - bottle?... I was really looking into the Kiinde Twist system, but it's stressing me out thinking 'what if I'm not even pumping enough per bag that she'd actually be eating two or more bottles per sitting?' I'm just confused. 
If you pump into bags, when and how much are you transferring to bottles to make sure baby is getting enough? ...I have no idea what I'm doing :(