I know my landlord does not really enjoy being a landlord.
At least in my state, it is almost impossible to evict non paying tenants who have children. (My landlord is having that problem now with the family on the first floor of our 3 family house - Chris, Monty and I rent the top floor.) From what I've heard (keeping in mind this is just from my landlord and one other person I know who is a landlord), being a landlord really , really kind of , well, to put it bluntly, sucks.
I know there are all sorts of laws here about not discriminating when you are picking applicants to rent. Not my landlord, but my old landlord who is no longer a landlord was sued by some people who claimed he did not rent to them soley based on their ethnicity (it had nothing to do with their ethnicity, he did not rent to them because they were scummy people who had no good references). The cost of fighting it was not worth it and he ended up paying them a fairly decent sum of money just to avoid going to court.
From what I have seen of our landlords struggle with our first floor people, they pay their rent about once every 6 months (not in full). There are now 8 of them living in a 2 BR apartment

. This is a fairly nice neighborhood made up of single & double family homes and the neighbors have complained about these people more than once, and our landlord has had to pay fines for stuff they've done. The cops have been called in more than once (occasionally by us & the second floor family) to get these people to keep the noise down.
Thus far, our landlord has told us he is trying to evict them, but since the woman has 5 kids living there, he doubts he will be able to get them out. They have TRASHED the place too.
I hope this doesn't discourage you, just approach it carefully if you do decide to become a landlord.