Starting baby on solids?

my so whom is 4 months old got the go ahead to start solids.. i know the rule about 1 new food every 4-5 days i also know studies show not to start until 6 months so i dont need to hear that im starting him too early.. what i was woundering was... how much did you start you child out in 1 day.. like if i were to get the 2 pack plastic gerber foods, should i feed him 1 pack at 1 feeding plus a bottle? i was only giving him 1/2 a pack at 1 feeding but he seems to want more.( he finishes 1/2 a pack in like a minute or 2) how many feedings do you give solids? 1?2?3? another thing i know your supposed to start at stage 1 food but there no difference in stage 1 and 2 other then the thickness and my son seems to perfer the thicker, would it be okay to give him stage 2?