Brochures or annual reports contain summaries of activities. Look out for details in newspapers and the scientific press. If you are applying for an academic post, it might be a good idea to have a look at past publications of the research group. Think about what questions you can ask at the interview, if you leave it until the last minute your mind will go blank. Check travelling times, you do not want to be late.
Some employers have a particular dress code.
If this is likely to be the case, ask in advance for guidance so you can dress appropriately on the day. Think about the questions you may be asked. If the job requires particular technical knowledge or skills, brush up on them. Many jobs require good communication skills. This is easier said than done and can require a great deal of thought.