I'm an almost finished engineer, and have started working (as an engineer) on the side of my studies. I do what the other engineers do, no more and no less. My discipline is engineering physics with a specialization in simulation (so lots of math and numerical analysis) and I work for a large telephony company with testing and validation.
A normal day:
I arrive at work, have some tea and fruit for breakfast and sit down at my computer, which is hooked to some bench-type multimeters. I fire up Eclipse + MATLAB and start cracking at today's problems. I answer the questions colleagues have for me on technical issues, and when I get stuck I get up from my desk and ask one of them for advice. I do this until I need to attend a meeting with clients or management. Repeat until lunch, repeat until end of day.
Good parts:
On a good day, I will arrive and start working on my part of the project we're doing and nobody bothers me until I need to go home. Then the day feels short and productive, with exciting things to think about. Everyone in my workplace is at least a bit smart, so workplace conversation is never incredibly bad (i previously worked in construction... those guys aren't as enlightened, in general).
I learn new things every day from just talking to people about what they are doing, and since most people wanted to become the engineers they now are my surroundings are filled with content, generally happy human beings. This has a huge effect on the day-to-day drudge. I get very flexible hours, and people generally trust me and talk to me in a decent way.
Bad Parts:
I only work on incredibly small parts of the finished product, as does everyone else - I never get to see "my" work in action, since it's hidden away in the depths of a driver or subroutine. Meetings can get frustrating, especially with management who want things done without understanding how their allocation of resources on my projects are affecting me. Overtime can be a real drag, especially ordered overtime that I can't control. Did you have plans for the weekend? Sorry, client needs a patch. Also, very strict corporate structures feel inflexible and inefficient - but that's mostly my company.
Hope to be of some help.
EDIT: In response to a previous answer, I actually work on problems and solve them with the skills I learned at university. Not schoolbook-type problems, of course, but reminiscent of the project-type assignments I do at university. Except there is no guidance most of the time.