Once you look at comparables on craigslist to see if you can rent for more than your mortgage + insurance + costs, decide how much time you want to spend on this endeavor. If the money is good (say you can rent for $2,000, and your mortgage and insurance etc. are $1,000) and you don't want to spend more time on it, then call a rental agency. If you can't make that much, or you have time to spend, then you need to research the rules about landlording- How to find renters, how to advertise, rules about how quickly you need to repair things, get leases put together, etc. Once you know the rate the agency will charge, the market rent, and how much time it will take to be a landlord, decide if that is worth it to you.
Then look at where you'd move- are you thinking of renting or buying something? What would be the total monthly cost of your alternative housing arrangement? (consider your utilities would probably go down, maybe commute down?)
The "worth it" point is different. Maybe $100 a month is worth it to you, maybe it would take $300 or $500 a month profit to make it worth it. I think if your "profit" is less than $500/mo, you need to think carefully about how often you'll need to repaint/ fix things/ replace carpet/ or have the house empty based on tenants. (You could run through a year's profit on a $2,000 rental at $500/mo profit, in just 2 months of vacancy and expenses to paint, care for the yard, and clean up the place from a bad tenant.)