At his office I wasn't simply getting coffee for the team or faxing papers, but I was able to go out and work with members of the community to collect insight into what constituents wanted to see out of their state government. I was able to research, find gaps in the Illinois budget, and propose plans which worked to see these needs covered.
What I wish was different
My only wish is that I'd had more time in this office. A lot of the time it feels like you're doing very little, but in the long run, what you do has a lot of impact. If you work there in the winter, it is going to be a much different experience than when you work for them in the summer (when it is not campaign season)
Advice
To do this type of experience, you need to be very outgoing and willing to step out of your comfort range. A lot of constituents might disagree with you, and you have to be able to still hold a meaningful conversation with that person. In addition, you are talking about some very sensitive topics, so you have to be able to be approachable and willing to engage with folks and discuss their thoughts and opinions.
