As people have said here its not the ideal career for money making. Although I think that is a good thing, because if people wanted to get into it for money then they wouldn't be in it for the people.
Saying that they money isn't horrible, you should be able to get by fine. Like most organisations, if you stuck with something then you would probably be able to work your way up, maybe to some kind of youth centre manager or something.
I always imagine social workers working with youth, and thats what i was interested in doing for a bit but I decided I don't have nearly enough compassion, patience and understanding. Maybe one day I will and then I can do an extra course in it.
I think it could be a good career, its not all stuck behind a desk. You get to meet people, probably go places, and really get involved in peoples lives, unlike doctors or anything. But there will be the burdens, and you will probably responsible sometimes, its hard meeting people and seeing that their lives aren't great and feeling helpless about it. But it makes you grateful, and makes you care. Sorry, i'm rambling. I wish I did social work instead.
Anyway if you are unsure, and its possible that later you change your mind, instead of doing just a B of Social Work do a BArts/BSocial Work, so you sort of have a fall back of Arts. I think its only a year extra, if any, and you can do Sociology, which is my major and fun and probably relevant.
If you want to do it, then do it, screw the money.