|Get ready to use on of these pipettes, A LOT|
Most supervisors are generally nice, fair and very very very busy. Some of them may expect a lot of hours from you (but that's just because they are so passionate about their field) while others are more lenient, however they are always always very busy. Some supervisors can be a bit critical and not be great teachers, but most of them are very good teachers and understand that this is still a learning experience. Having a good relationship with your supervisor can only be helpful (particularly when it comes to making connections in the future), however the amount you get back from your supervisor can vary a lot with some being very friendly and others strictly professional.
For the vast majority of cases you can expect the people you work with on a daily basis to be friendly, helpful and intelligent. You can expect there to be quite a lot of diversity, particularly if you go to an international institution. Again you will sometimes encounter someone who is less than sociable or unwilling to help, but the amount of people who are friendly and helpful vastly outweighs them. Creating a close group or groups of friends at a similar stage to you will be very helpful to you whilst you're there, not only to keep up morale and learn but also to explore ideas and form new friendships that could last for years and years.
|This is what your typical lab would look like|
You will have a lot of work to do and organisation is key. Planning your experiments and maintaining a healthy work-life balance can be tricky but is also very doable. My advice is to always allow at least 1.5x the amount of time you think it will take because something will almost always go wrong! Normally the actual techniques aren't too technically demanding but you need to stay focused as it is easy to lose concentration and mess things up. Be prepared for your experiments to not work most of the time (this just makes the times it does work even better!) and spend a lot of time in front of a screen either reading or writing up your experiments.
If you're thinking of going into research for a career and you have the opportunity to try it out then I heavily recommend doing so; if it doesn't work out you at least have a years worth of experience under your belt and you know that it isn't the job for you, and if it does you have. Be prepared to work, make connections and enjoy yourself!