Yeah I did it for a few years when I was at uni, the job is not just collections but sales, you have targets to meet. Pretty easy, got to keep on top of your book, can be hard to work out at first, a rather awkward system, well it was when I did it. apart from that the only other, but main problem is the customers.
Some will be great others will hate you, abuse you and threaten you, and some of the houses you have to visit are beyond bleedin awful. Have work clothes that you only wear for that, because you will come home reaking!
Also be aware of your walk, thats your area, know the dodgy areas, try to do these in the day, be aware of the characters, dont put yourself in any silly situations. There will be people on the estates that know who you are and where you will be at certain times, and they know you carry money, being robbed is always a possibility.
Apart from all that. I loved it, you have a certain amount of freedom, you get to meet all kinds of people and the pay for the hours can be very good.
Hope i was helpful, just keep your wits about you, oh and the good payers are like gold dust treat them well, they will be your best friends when you are having a bad week and no bugger is paying, they make your book look mildly reasonable.
Good luck, and dont fall for the million excuses you will hear, take it all with a pinch of salt, and be firm but fare!