I actually did quite well in the industry and worked in general industrial (arms and legs), commercial (office staff), HR, Finance, Branch Manager etc etc.
In my first year I earnt a basic of around £16k, with bonuses it went up to just over £32kish - which wasn't bad, but to put it in perspective, I had a storming year and grew my business unit to the 2nd largest in the company.
In finance, with experience and working in a very long hours culture, I earnt £50k overall in first year, with around £23k of this in bonus. Very Very hard work and usually a 50 hour week with a long commute to a hellish place, that I both loved and hated.
You need to find a niche that suits, a level of candidate that you can relate to (ie I wouldn;t recommend that a young graduate out of uni goes straight into recruitment at director level), a company where you like the culture and a working environment that is suitable.
Otherwise, if you are hungry, a bit ruthless if you need to be, savvy and business minded it can be a very enjoyable job.
But blumin hard work!
Hope this helps