Stupid question - routine

I know I'll sound like an idiot but how do I get my baby into a routine? I do put him to bed at more or less the same time every night but some nights he wakes once, sometimes every hour and a half. He is bottle fed and has anywhere from 2 to 4 oz with anywhere between 1 and 5 hours between bottles. How do I get him into a sleep/eat routine? I barely sleep at night thinking he'll wake up any minute. Twice this week he's woken five minutes after I've got to sleep but sometimes he'll go for hours.