Licences and contracts?

[TheStupidForeigner]

So tomorrow I will have my first paid photoshoot, wohoo! It will be quite straight forward and the client is very friendly so I don't expect any problems but I wanted to ask what paper work I might need to prepare? Specifically if they want something official giving them the rights to use the photos? I prefer to keep it as simple and friendly as possible but just in case they request something I would also like to seem professional in case they want to hire me again or refer me to someone else