Honestly, it depends all on you :]
I'm going to be a junior come fall and I started research 2nd semester my freshman year. I've worked in another lab back home since high school, but that was a bit more flexible.
It would be a wise idea to go ahead and start looking at professors who have a field that you are interested in researching and contact them. It might even be possible to set up an interview with them to have them show you around the lab, meet the other students, and discuss what both of your goals are for doing research. You don't want someone who is too lax, but you don't want someone who wants to have you in their lab just to shove publications down your throat (I've had a personal experience with that at a summer internship - no bueno). Tenure could also be weighty factor because non-tenured professors tend to push publications for grant money apart from the amount that the university gives them. You can ask whether you'll be working more closely associated with them, their grad students, or a 50/50 split.
I interviewed about ~5 professors at my institution. You get a feel for the professor and the other students you work with should give you a level of comfortability. Both of my labs (at school and home) have hard working students, but we know how to have fun too. You don't want all work and no play! One lab I visited, I loved the professor and her topic, but her grad students weren't welcoming, and none of them looked particularly happy to be there.
If you're really looking to do research to get the experience and not just make some extra cash, you will have to devote some time to your lab.
It is essentially a job. Depending on your lab, the hours you go in will be different too.
The professor I work with at my school (professor 1)wants me a minimum of 10 hours per week, at least 3 days a week, but I know for him that means at least 15 hours a week. I work with proteins. Sometimes I had to get up early to go induce proteins, and come back during lunch or after class to harvest them and do whatever. I went in some weekends too.I'm a double major, and his opinion is outside of class, I should be in the lab and that nothing but biochemistry matters lol. This professor also is not tenured, so he pushes publications and though I like the challenge, sometimes I feel he can push a bit too much.
The other professor (professor 2) I work with here at home is much more laid back, he's NSF sponsored, and quite flexible. If you need to take a day off, he's not at all bothered by it, but our lab WORKS. We're there all day, and I love it. For the summer, I'm there ~25 hours a week and I'm taking organic+lab this summer, so work ~25 hours a week + 17 hours of class. this is my computational chem lab. I go in, and at 5, we're done and we just finish our programs up the next day. He's open to being a more well rounded person with clubs and sports - not just all science. It all depends!
You do learn a lot from your lab. I love both professors dearly, but you'll have to learn to balance ECs, classes, lab, and you time. Professors are generally accommodating to class schedules and all else. They (and you) have to remember you're a student too! Freshman year, I taught elementary school strings, did research, took 17 credits, did orchestra etc etc. Balance is the key. If something is too much, you have to let it go or you'll suffer burnout. I did that. I kept what was most important/valuble to me, and let the others go. Sophomore year research was put on the back burner because I was taking an inordinate amount of credits and added in being an RA, but I'm
returning in the fall which may mean a class or two less. We'll see.
Oh! Also ask IF they pay their students. My freshman year I got paid by a campus research fellowship program, not my professor. Professor #1 has just recently stopped paying his students and will only offer students undergrad credit.
All the best!
