A route plan or map 2. Yourself, wearing smart clothes 3. Your mobile phone to call them in case you are delayed 4. The name and details of the person you are meeting 5. Your C.V. 6. Your bank details and P45 7. The job description and person specification for the job 8. The application form or letter you have already sent them 9. The contact details for your references 10. Your certificates and licences 11. Information about the company 12. Your portfolio or examples of your work if you have them
The more information you can provide them the easier and faster it is for them to hire you. Dont volunteer all of the above, just have it ready in case you need it. Some of the information, like company info, the job description, your application and your C.V. is useful for you to revise from before you go in to the interview. You may not need everything in the end, but its better to have it and not need it than need it and not have it.