Learning
You are here to create knowledge.
In order to do this, you first of all need to learn as much as possible. You need to know what others have already done in the past, and what the state of the current knowledge in your field is. Only then you can come up with novel ideas, ask innovative questions, and advance your field. You need to know as much as possible if you want to make good use of your time here in our labs and the available ressources and equipment.
Reading text books and the primary literature is of utmost importance! You should really read a lot (in this I agree with the otherwise controversially discussed letter of Prof Gassmann ...).
Our university offers courses for PhD students. Have a look at the courses at the InGrA homepage.
Also, many great courses are offered for all employees of the University. A list of these courses can be found here - well worth taking a look and booking for you own career and personal development!
Visit talks and listen to other scientists. Talks in Halle are e.g. summarized in the "Kalender Biowissenschaften", but there are other talks that do not appear here - I will keep my students posted when I get aware of interesting talks.
Become part of a scientific community and join scientific societies that bring together like-minded scientists. Keep an eye open for conferences that might not only interest you, but also other members of the group. I will also suggest conferences you should visit. My aim is that everyone of you will visit one conference a year - if you have at least a poster to present.